<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2025 Workiva-->
<!--r:6b1aa075-2709-4cd8-aae9-83c875b10fd4,g:996cd083-41e3-41df-9a4d-a4ac450a20e2-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.trimascorp.com/role/DocumentandEntityInformationDocument" xlink:type="simple" xlink:href="trs-20241231.xsd#DocumentandEntityInformationDocument"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DocumentandEntityInformationDocument" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitiesTable_4f967c98-c609-4df2-ac6b-1094db1216bb" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntitiesTable_4f967c98-c609-4df2-ac6b-1094db1216bb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_9c68d2d7-ce13-4d4e-8d60-3bc8d7caaebd" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_4f967c98-c609-4df2-ac6b-1094db1216bb" xlink:to="loc_dei_LegalEntityAxis_9c68d2d7-ce13-4d4e-8d60-3bc8d7caaebd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_9c68d2d7-ce13-4d4e-8d60-3bc8d7caaebd_default" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_9c68d2d7-ce13-4d4e-8d60-3bc8d7caaebd" xlink:to="loc_dei_EntityDomain_9c68d2d7-ce13-4d4e-8d60-3bc8d7caaebd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_8f8318e1-d2ed-425f-91e5-ea7ac5caa723" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_9c68d2d7-ce13-4d4e-8d60-3bc8d7caaebd" xlink:to="loc_dei_EntityDomain_8f8318e1-d2ed-425f-91e5-ea7ac5caa723" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_3ae8d18b-191b-439f-8115-56bdcdd47f13" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_Security12bTitle_3ae8d18b-191b-439f-8115-56bdcdd47f13" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_df7139a1-886e-428a-8520-b103ea517a27" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityIncorporationStateCountryCode_df7139a1-886e-428a-8520-b103ea517a27" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentAnnualReport_0322b3bc-df38-4b8f-91bd-b8ea36dfa8b7" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentAnnualReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_DocumentAnnualReport_0322b3bc-df38-4b8f-91bd-b8ea36dfa8b7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_54a77371-7fda-4e09-8125-928f0b721473" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityRegistrantName_54a77371-7fda-4e09-8125-928f0b721473" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_12c9e238-cf97-4ff0-8b84-5cdf4c349910" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityAddressAddressLine1_12c9e238-cf97-4ff0-8b84-5cdf4c349910" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine2_dd791a65-6296-474e-af34-137cbc2d9189" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressAddressLine2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityAddressAddressLine2_dd791a65-6296-474e-af34-137cbc2d9189" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_57fea435-480e-40f3-9845-519ba9b76f6d" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityAddressCityOrTown_57fea435-480e-40f3-9845-519ba9b76f6d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_69a9f5af-e5c4-41aa-8159-fc1545b45903" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityAddressStateOrProvince_69a9f5af-e5c4-41aa-8159-fc1545b45903" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_a84fe00f-bde1-4def-90ef-ad90e742ae43" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityAddressPostalZipCode_a84fe00f-bde1-4def-90ef-ad90e742ae43" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_c90daa5d-c41c-4a28-9c70-b1cf89ec645a" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_CityAreaCode_c90daa5d-c41c-4a28-9c70-b1cf89ec645a" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_a49ad93d-f099-4099-a480-99815083a0bc" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_LocalPhoneNumber_a49ad93d-f099-4099-a480-99815083a0bc" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_4d20ff19-75f0-4b37-8d00-dff14186a834" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityCentralIndexKey_4d20ff19-75f0-4b37-8d00-dff14186a834" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CurrentFiscalYearEndDate_e70a6f60-6b87-43cf-a2c6-d99ab2906b5b" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_CurrentFiscalYearEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_CurrentFiscalYearEndDate_e70a6f60-6b87-43cf-a2c6-d99ab2906b5b" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFilerCategory_cc39349e-9a95-4774-ab12-9daddb0f596a" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityFilerCategory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityFilerCategory_cc39349e-9a95-4774-ab12-9daddb0f596a" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_f25729c9-aa40-4915-8647-e0ee5cba56a2" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_DocumentType_f25729c9-aa40-4915-8647-e0ee5cba56a2" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_06ec47e6-3c32-43f3-b9f3-c2a211dc959e" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityFileNumber_06ec47e6-3c32-43f3-b9f3-c2a211dc959e" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_040f1881-7410-4263-abd3-ebcb973711e4" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_DocumentPeriodEndDate_040f1881-7410-4263-abd3-ebcb973711e4" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalYearFocus_d902b31c-7217-43bb-a7a8-4e0636735ba1" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentFiscalYearFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_DocumentFiscalYearFocus_d902b31c-7217-43bb-a7a8-4e0636735ba1" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFiscalPeriodFocus_30f4b9dd-7b34-4ec8-9270-a60e4d42929f" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentFiscalPeriodFocus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_DocumentFiscalPeriodFocus_30f4b9dd-7b34-4ec8-9270-a60e4d42929f" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_77e7790a-afda-4afa-a009-4ded8fb3ea71" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_AmendmentFlag_77e7790a-afda-4afa-a009-4ded8fb3ea71" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_40ab9f4e-211b-449b-bc3a-4e1bfcf698ab" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityCommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_40ab9f4e-211b-449b-bc3a-4e1bfcf698ab" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityWellKnownSeasonedIssuer_e11067c4-eca3-4610-a66b-6b2076942f75" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityWellKnownSeasonedIssuer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityWellKnownSeasonedIssuer_e11067c4-eca3-4610-a66b-6b2076942f75" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityVoluntaryFilers_abf9904d-d2ff-4d1e-a48a-deedf4ee9c48" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityVoluntaryFilers"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityVoluntaryFilers_abf9904d-d2ff-4d1e-a48a-deedf4ee9c48" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCurrentReportingStatus_6408eb2a-87fb-499a-b00e-41c28d4885a7" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityCurrentReportingStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityCurrentReportingStatus_6408eb2a-87fb-499a-b00e-41c28d4885a7" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityInteractiveDataCurrent_f63e23a7-3247-44c2-a50b-0b5d762bf33f" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityInteractiveDataCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityInteractiveDataCurrent_f63e23a7-3247-44c2-a50b-0b5d762bf33f" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityPublicFloat_3dd5127a-c25b-4bb9-b842-109459b94d54" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityPublicFloat"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityPublicFloat_3dd5127a-c25b-4bb9-b842-109459b94d54" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntitySmallBusiness_596e3f8d-b52f-482a-9e62-19c3bf6a8b31" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntitySmallBusiness"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntitySmallBusiness_596e3f8d-b52f-482a-9e62-19c3bf6a8b31" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_6591c61b-23b2-444b-b7d3-73eded76fef4" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityEmergingGrowthCompany_6591c61b-23b2-444b-b7d3-73eded76fef4" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_IcfrAuditorAttestationFlag_40fb32c3-e9ac-4a0d-ad96-50509dfdf9d2" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_IcfrAuditorAttestationFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_IcfrAuditorAttestationFlag_40fb32c3-e9ac-4a0d-ad96-50509dfdf9d2" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentFinStmtErrorCorrectionFlag_735a7c54-165a-43d8-802b-a24fec6348cb" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentFinStmtErrorCorrectionFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_DocumentFinStmtErrorCorrectionFlag_735a7c54-165a-43d8-802b-a24fec6348cb" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityShellCompany_f8068666-fcdd-4be9-9160-cf68db460462" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityShellCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityShellCompany_f8068666-fcdd-4be9-9160-cf68db460462" xlink:type="arc" order="30"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentTransitionReport_ec40c2bb-440a-4d7e-b010-c32f4ac189f8" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_DocumentTransitionReport"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_DocumentTransitionReport_ec40c2bb-440a-4d7e-b010-c32f4ac189f8" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_ef6d395f-e9cd-48a5-a76c-e36d745c5b28" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_EntityTaxIdentificationNumber_ef6d395f-e9cd-48a5-a76c-e36d745c5b28" xlink:type="arc" order="32"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_156debe5-a9c9-4ccb-91af-26068fe62d05" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_TradingSymbol_156debe5-a9c9-4ccb-91af-26068fe62d05" xlink:type="arc" order="33"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_68e84cfd-5259-476d-bd34-56dbbf0a4d63" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_2023ea95-2553-4c70-a964-4df26c6d83fb" xlink:to="loc_dei_SecurityExchangeName_68e84cfd-5259-476d-bd34-56dbbf0a4d63" xlink:type="arc" order="34"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/AuditInformation" xlink:type="simple" xlink:href="trs-20241231.xsd#AuditInformation"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/AuditInformation" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_AuditorLineItems_62af8fa9-1d00-4898-a598-f01da31c1532" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AuditorLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AuditorTable_df06a0bb-dc91-40df-8091-98d8144efe3d" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AuditorTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_AuditorLineItems_62af8fa9-1d00-4898-a598-f01da31c1532" xlink:to="loc_dei_AuditorTable_df06a0bb-dc91-40df-8091-98d8144efe3d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_6d2a894e-53bc-4a85-93cb-fd11f56ef5e9" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_AuditorTable_df06a0bb-dc91-40df-8091-98d8144efe3d" xlink:to="loc_dei_LegalEntityAxis_6d2a894e-53bc-4a85-93cb-fd11f56ef5e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_6d2a894e-53bc-4a85-93cb-fd11f56ef5e9_default" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_6d2a894e-53bc-4a85-93cb-fd11f56ef5e9" xlink:to="loc_dei_EntityDomain_6d2a894e-53bc-4a85-93cb-fd11f56ef5e9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_e3458bcb-e90a-4ce9-91f6-602ce6be4f74" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_6d2a894e-53bc-4a85-93cb-fd11f56ef5e9" xlink:to="loc_dei_EntityDomain_e3458bcb-e90a-4ce9-91f6-602ce6be4f74" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AuditorLocation_b417f8ba-259a-4a66-bec1-d2e1bd1cad9f" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AuditorLocation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_AuditorLineItems_62af8fa9-1d00-4898-a598-f01da31c1532" xlink:to="loc_dei_AuditorLocation_b417f8ba-259a-4a66-bec1-d2e1bd1cad9f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AuditorName_a70f7241-4433-45c3-b4f9-81647d9e9f86" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AuditorName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_AuditorLineItems_62af8fa9-1d00-4898-a598-f01da31c1532" xlink:to="loc_dei_AuditorName_a70f7241-4433-45c3-b4f9-81647d9e9f86" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AuditorFirmId_493b6581-ca10-4eda-92ef-004d9cd74553" xlink:href="https://xbrl.sec.gov/dei/2024/dei-2024.xsd#dei_AuditorFirmId"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_AuditorLineItems_62af8fa9-1d00-4898-a598-f01da31c1532" xlink:to="loc_dei_AuditorFirmId_493b6581-ca10-4eda-92ef-004d9cd74553" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/ConsolidatedStatementofShareholdersEquityStatement" xlink:type="simple" xlink:href="trs-20241231.xsd#ConsolidatedStatementofShareholdersEquityStatement"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/ConsolidatedStatementofShareholdersEquityStatement" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_4857c95b-6b28-4827-848b-8c8c4a056baa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_c699ae8b-fdcf-4d7f-83b8-56ac670047f6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_4857c95b-6b28-4827-848b-8c8c4a056baa" xlink:to="loc_us-gaap_StatementTable_c699ae8b-fdcf-4d7f-83b8-56ac670047f6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_d8150a11-9ea6-4e21-a9eb-77da314de8b8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_c699ae8b-fdcf-4d7f-83b8-56ac670047f6" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_d8150a11-9ea6-4e21-a9eb-77da314de8b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_d8150a11-9ea6-4e21-a9eb-77da314de8b8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_d8150a11-9ea6-4e21-a9eb-77da314de8b8" xlink:to="loc_us-gaap_EquityComponentDomain_d8150a11-9ea6-4e21-a9eb-77da314de8b8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_36fb15ef-11cb-4dbc-b922-8d73ec20d782" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_d8150a11-9ea6-4e21-a9eb-77da314de8b8" xlink:to="loc_us-gaap_EquityComponentDomain_36fb15ef-11cb-4dbc-b922-8d73ec20d782" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_e1f2badb-d03a-4776-a03b-e80faec786d1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_36fb15ef-11cb-4dbc-b922-8d73ec20d782" xlink:to="loc_us-gaap_CommonStockMember_e1f2badb-d03a-4776-a03b-e80faec786d1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_53282158-c6c8-49c6-9fbf-b0d0a807a3f7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_36fb15ef-11cb-4dbc-b922-8d73ec20d782" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_53282158-c6c8-49c6-9fbf-b0d0a807a3f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_e5da4c47-634e-4db7-a0fc-7d3b5eab6075" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_36fb15ef-11cb-4dbc-b922-8d73ec20d782" xlink:to="loc_us-gaap_RetainedEarningsMember_e5da4c47-634e-4db7-a0fc-7d3b5eab6075" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8d23c298-8338-4d13-a563-645150007d8f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_36fb15ef-11cb-4dbc-b922-8d73ec20d782" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8d23c298-8338-4d13-a563-645150007d8f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_13a38e0f-e369-44e7-82c7-f56c40fbaf4e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4857c95b-6b28-4827-848b-8c8c4a056baa" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_13a38e0f-e369-44e7-82c7-f56c40fbaf4e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_f015eff6-6826-4b8b-b5a2-800bc5364683" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4857c95b-6b28-4827-848b-8c8c4a056baa" xlink:to="loc_us-gaap_NetIncomeLoss_f015eff6-6826-4b8b-b5a2-800bc5364683" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_11e29677-7ecf-4148-923b-2fc6be407da2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4857c95b-6b28-4827-848b-8c8c4a056baa" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_11e29677-7ecf-4148-923b-2fc6be407da2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_20550a30-81e0-4c01-ace9-c47131fa5525" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4857c95b-6b28-4827-848b-8c8c4a056baa" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_20550a30-81e0-4c01-ace9-c47131fa5525" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_0927d465-ef9b-43c9-a988-997421eee5ae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4857c95b-6b28-4827-848b-8c8c4a056baa" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_0927d465-ef9b-43c9-a988-997421eee5ae" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_f478f370-de79-486a-be96-5843d463ec2c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4857c95b-6b28-4827-848b-8c8c4a056baa" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_f478f370-de79-486a-be96-5843d463ec2c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationGross_ebd0c334-3f1a-40c0-8da0-7ea497654fd0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4857c95b-6b28-4827-848b-8c8c4a056baa" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensationGross_ebd0c334-3f1a-40c0-8da0-7ea497654fd0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_0092c0cd-e38d-4fa1-8b25-27639bfb8a11" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4857c95b-6b28-4827-848b-8c8c4a056baa" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_0092c0cd-e38d-4fa1-8b25-27639bfb8a11" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings_1beed369-fc67-4533-8262-56dfbfcf2608" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4857c95b-6b28-4827-848b-8c8c4a056baa" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalDividendsInExcessOfRetainedEarnings_1beed369-fc67-4533-8262-56dfbfcf2608" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStockCash_a6d0f23c-36ff-4e87-b199-5f4d5cc21ba4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsCommonStockCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4857c95b-6b28-4827-848b-8c8c4a056baa" xlink:to="loc_us-gaap_DividendsCommonStockCash_a6d0f23c-36ff-4e87-b199-5f4d5cc21ba4" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ImpactOfAdoptionOfNewAccountingPronouncement_575939e9-241e-4377-bf48-560a7074f7cb" xlink:href="trs-20241231.xsd#trs_ImpactOfAdoptionOfNewAccountingPronouncement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_4857c95b-6b28-4827-848b-8c8c4a056baa" xlink:to="loc_trs_ImpactOfAdoptionOfNewAccountingPronouncement_575939e9-241e-4377-bf48-560a7074f7cb" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_e5ed3095-f548-446b-aab9-55a60dd1cb55" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/SubsequentEventsNotes" xlink:type="simple" xlink:href="trs-20241231.xsd#SubsequentEventsNotes"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SubsequentEventsNotes" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_67f01ee7-64ac-4820-b397-6404ca891e73" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_9a291ec7-9d17-42a6-ac9f-08025923c398" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_67f01ee7-64ac-4820-b397-6404ca891e73" xlink:to="loc_us-gaap_SubsequentEventTable_9a291ec7-9d17-42a6-ac9f-08025923c398" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_1d158891-a825-47e3-a727-a5b7de1f9f96" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_9a291ec7-9d17-42a6-ac9f-08025923c398" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_1d158891-a825-47e3-a727-a5b7de1f9f96" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_1d158891-a825-47e3-a727-a5b7de1f9f96_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_1d158891-a825-47e3-a727-a5b7de1f9f96" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_1d158891-a825-47e3-a727-a5b7de1f9f96_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_06655e65-5b4f-4c2c-a117-c024866e0e60" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_1d158891-a825-47e3-a727-a5b7de1f9f96" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_06655e65-5b4f-4c2c-a117-c024866e0e60" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventsTextBlock_283911c8-3ef8-4efa-8cbd-d24ef95b0c41" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventsTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_67f01ee7-64ac-4820-b397-6404ca891e73" xlink:to="loc_us-gaap_SubsequentEventsTextBlock_283911c8-3ef8-4efa-8cbd-d24ef95b0c41" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EarningsperShareEarningsperShareTables" xlink:type="simple" xlink:href="trs-20241231.xsd#EarningsperShareEarningsperShareTables"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EarningsperShareEarningsperShareTables" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDilutedLineItems_9643eb98-c202-4b89-9bdd-ec1905da7d3d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareDilutedLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable_237253e3-f006-4db3-8e91-489ad612de32" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EarningsPerShareDilutedLineItems_9643eb98-c202-4b89-9bdd-ec1905da7d3d" xlink:to="loc_us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable_237253e3-f006-4db3-8e91-489ad612de32" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_80f8c13a-bf1d-4dcf-96b6-6c62a9e9b755" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable_237253e3-f006-4db3-8e91-489ad612de32" xlink:to="loc_us-gaap_StatementClassOfStockAxis_80f8c13a-bf1d-4dcf-96b6-6c62a9e9b755" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_80f8c13a-bf1d-4dcf-96b6-6c62a9e9b755_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_80f8c13a-bf1d-4dcf-96b6-6c62a9e9b755" xlink:to="loc_us-gaap_ClassOfStockDomain_80f8c13a-bf1d-4dcf-96b6-6c62a9e9b755_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_25e5ddfa-286d-4e2d-a306-7b126101e1df" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_80f8c13a-bf1d-4dcf-96b6-6c62a9e9b755" xlink:to="loc_us-gaap_ClassOfStockDomain_25e5ddfa-286d-4e2d-a306-7b126101e1df" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock_72dbbc35-f119-4b75-ae91-31143d67e221" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedLineItems_9643eb98-c202-4b89-9bdd-ec1905da7d3d" xlink:to="loc_us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock_72dbbc35-f119-4b75-ae91-31143d67e221" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/SummaryofSignificantAccountingPoliciesDepreciationandAmortizationDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#SummaryofSignificantAccountingPoliciesDepreciationandAmortizationDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SummaryofSignificantAccountingPoliciesDepreciationandAmortizationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_trs_PropertyPlantAndEquipmentAndFiniteLivedIntangibleAssetsLineItems_29ebfb72-448d-4c0d-a08d-555cf82c6079" xlink:href="trs-20241231.xsd#trs_PropertyPlantAndEquipmentAndFiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ScheduleOfPropertyPlantAndEquipmentAndFiniteLivedIntangibleAssetsTable_d4bb2d29-0234-4812-80ac-37c8699b6dd0" xlink:href="trs-20241231.xsd#trs_ScheduleOfPropertyPlantAndEquipmentAndFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_trs_PropertyPlantAndEquipmentAndFiniteLivedIntangibleAssetsLineItems_29ebfb72-448d-4c0d-a08d-555cf82c6079" xlink:to="loc_trs_ScheduleOfPropertyPlantAndEquipmentAndFiniteLivedIntangibleAssetsTable_d4bb2d29-0234-4812-80ac-37c8699b6dd0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_d0a86a5e-97dc-4839-b0bd-1146ef12ba67" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfPropertyPlantAndEquipmentAndFiniteLivedIntangibleAssetsTable_d4bb2d29-0234-4812-80ac-37c8699b6dd0" xlink:to="loc_srt_RangeAxis_d0a86a5e-97dc-4839-b0bd-1146ef12ba67" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_d0a86a5e-97dc-4839-b0bd-1146ef12ba67_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_d0a86a5e-97dc-4839-b0bd-1146ef12ba67" xlink:to="loc_srt_RangeMember_d0a86a5e-97dc-4839-b0bd-1146ef12ba67_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_25a04105-bdf2-46e6-a7de-8d9fefb773dd" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_d0a86a5e-97dc-4839-b0bd-1146ef12ba67" xlink:to="loc_srt_RangeMember_25a04105-bdf2-46e6-a7de-8d9fefb773dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_e2bc6eb4-c4cb-418f-930e-688dbff60fb4" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_25a04105-bdf2-46e6-a7de-8d9fefb773dd" xlink:to="loc_srt_MinimumMember_e2bc6eb4-c4cb-418f-930e-688dbff60fb4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_331a0a4b-5b85-4188-b441-4280155e2645" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_25a04105-bdf2-46e6-a7de-8d9fefb773dd" xlink:to="loc_srt_MaximumMember_331a0a4b-5b85-4188-b441-4280155e2645" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c7b690c4-2b38-4ae1-93c2-5a0608467a7d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfPropertyPlantAndEquipmentAndFiniteLivedIntangibleAssetsTable_d4bb2d29-0234-4812-80ac-37c8699b6dd0" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c7b690c4-2b38-4ae1-93c2-5a0608467a7d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c7b690c4-2b38-4ae1-93c2-5a0608467a7d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c7b690c4-2b38-4ae1-93c2-5a0608467a7d" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c7b690c4-2b38-4ae1-93c2-5a0608467a7d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_01192155-8510-423b-9fd5-388f504b3d48" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c7b690c4-2b38-4ae1-93c2-5a0608467a7d" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_01192155-8510-423b-9fd5-388f504b3d48" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandBuildingsAndImprovementsMember_6d6208c9-daa8-411d-93a6-82d3a7628414" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LandBuildingsAndImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_01192155-8510-423b-9fd5-388f504b3d48" xlink:to="loc_us-gaap_LandBuildingsAndImprovementsMember_6d6208c9-daa8-411d-93a6-82d3a7628414" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_376d90ea-042f-448c-8222-28badd0acdfa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_01192155-8510-423b-9fd5-388f504b3d48" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_376d90ea-042f-448c-8222-28badd0acdfa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandBuildingsAndImprovementsMember_d947328a-12a3-4eb4-8af7-622e258075c7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LandBuildingsAndImprovementsMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_9e02b87e-8954-47f4-913f-47744c443508" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_a5ed0051-72e2-411d-8eba-a5379d66f1ec" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfPropertyPlantAndEquipmentAndFiniteLivedIntangibleAssetsTable_d4bb2d29-0234-4812-80ac-37c8699b6dd0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_a5ed0051-72e2-411d-8eba-a5379d66f1ec" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_a5ed0051-72e2-411d-8eba-a5379d66f1ec_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_a5ed0051-72e2-411d-8eba-a5379d66f1ec" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_a5ed0051-72e2-411d-8eba-a5379d66f1ec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0e1ad048-25ca-4d5a-ba43-808181d29158" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_a5ed0051-72e2-411d-8eba-a5379d66f1ec" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0e1ad048-25ca-4d5a-ba43-808181d29158" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_06461b6b-dd55-47d2-b12f-32c1bf261b1b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0e1ad048-25ca-4d5a-ba43-808181d29158" xlink:to="loc_us-gaap_CustomerRelationshipsMember_06461b6b-dd55-47d2-b12f-32c1bf261b1b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_TechnologyAndOtherMember_32624837-dce3-455d-8fad-134937436457" xlink:href="trs-20241231.xsd#trs_TechnologyAndOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0e1ad048-25ca-4d5a-ba43-808181d29158" xlink:to="loc_trs_TechnologyAndOtherMember_32624837-dce3-455d-8fad-134937436457" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_20b98ddc-bc8e-4e33-8e1d-d2bf31c7ef51" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_PropertyPlantAndEquipmentAndFiniteLivedIntangibleAssetsLineItems_29ebfb72-448d-4c0d-a08d-555cf82c6079" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_20b98ddc-bc8e-4e33-8e1d-d2bf31c7ef51" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_84b8f5ac-2a79-4b9e-8aea-48c98b12a255" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_PropertyPlantAndEquipmentAndFiniteLivedIntangibleAssetsLineItems_29ebfb72-448d-4c0d-a08d-555cf82c6079" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_84b8f5ac-2a79-4b9e-8aea-48c98b12a255" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/SummaryofSignificantAccountingPoliciesHighDeductibleInsuranceDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#SummaryofSignificantAccountingPoliciesHighDeductibleInsuranceDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SummaryofSignificantAccountingPoliciesHighDeductibleInsuranceDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_trs_InsurancecoverageLineItems_72b79d85-df53-4bb4-9d9e-455350f0ef30" xlink:href="trs-20241231.xsd#trs_InsurancecoverageLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ScheduleofinsurancecoverageTable_5fd8f7b0-6171-45ad-8848-cf578f029494" xlink:href="trs-20241231.xsd#trs_ScheduleofinsurancecoverageTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_trs_InsurancecoverageLineItems_72b79d85-df53-4bb4-9d9e-455350f0ef30" xlink:to="loc_trs_ScheduleofinsurancecoverageTable_5fd8f7b0-6171-45ad-8848-cf578f029494" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_07dd48ea-518f-4aa4-88e4-d7660075a287" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleofinsurancecoverageTable_5fd8f7b0-6171-45ad-8848-cf578f029494" xlink:to="loc_srt_RangeAxis_07dd48ea-518f-4aa4-88e4-d7660075a287" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_07dd48ea-518f-4aa4-88e4-d7660075a287_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_07dd48ea-518f-4aa4-88e4-d7660075a287" xlink:to="loc_srt_RangeMember_07dd48ea-518f-4aa4-88e4-d7660075a287_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_001248fb-2be0-4847-9b08-52c7e999057c" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_07dd48ea-518f-4aa4-88e4-d7660075a287" xlink:to="loc_srt_RangeMember_001248fb-2be0-4847-9b08-52c7e999057c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_aa6de95a-4b6b-439d-ad95-683b3685adc2" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_001248fb-2be0-4847-9b08-52c7e999057c" xlink:to="loc_srt_MinimumMember_aa6de95a-4b6b-439d-ad95-683b3685adc2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_a7352a9e-53bc-4943-a380-8c91780c528e" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_001248fb-2be0-4847-9b08-52c7e999057c" xlink:to="loc_srt_MaximumMember_a7352a9e-53bc-4943-a380-8c91780c528e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_InsuranceTypeAxis_ea324baf-5597-46df-a4d3-6ce58ccb4ff9" xlink:href="trs-20241231.xsd#trs_InsuranceTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleofinsurancecoverageTable_5fd8f7b0-6171-45ad-8848-cf578f029494" xlink:to="loc_trs_InsuranceTypeAxis_ea324baf-5597-46df-a4d3-6ce58ccb4ff9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_InsuranceTypeDomain_ea324baf-5597-46df-a4d3-6ce58ccb4ff9_default" xlink:href="trs-20241231.xsd#trs_InsuranceTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_InsuranceTypeAxis_ea324baf-5597-46df-a4d3-6ce58ccb4ff9" xlink:to="loc_trs_InsuranceTypeDomain_ea324baf-5597-46df-a4d3-6ce58ccb4ff9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_InsuranceTypeDomain_36ad757d-5de6-4f78-9ef6-08a2f1a75312" xlink:href="trs-20241231.xsd#trs_InsuranceTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_InsuranceTypeAxis_ea324baf-5597-46df-a4d3-6ce58ccb4ff9" xlink:to="loc_trs_InsuranceTypeDomain_36ad757d-5de6-4f78-9ef6-08a2f1a75312" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_WorkersCompensationMember_c11bcba7-ad8e-430d-8c7a-c6cb2a785ce9" xlink:href="trs-20241231.xsd#trs_WorkersCompensationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_InsuranceTypeDomain_36ad757d-5de6-4f78-9ef6-08a2f1a75312" xlink:to="loc_trs_WorkersCompensationMember_c11bcba7-ad8e-430d-8c7a-c6cb2a785ce9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeneralLiabilityMember_e02ae4cf-2606-435c-aa95-5888f7f1d094" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeneralLiabilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_InsuranceTypeDomain_36ad757d-5de6-4f78-9ef6-08a2f1a75312" xlink:to="loc_us-gaap_GeneralLiabilityMember_e02ae4cf-2606-435c-aa95-5888f7f1d094" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_GroupMedicalPlanMember_42ad7925-ba5c-4594-8dfc-1e2879581ae6" xlink:href="trs-20241231.xsd#trs_GroupMedicalPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_InsuranceTypeDomain_36ad757d-5de6-4f78-9ef6-08a2f1a75312" xlink:to="loc_trs_GroupMedicalPlanMember_42ad7925-ba5c-4594-8dfc-1e2879581ae6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_MaximumRetention_ff7e4496-8850-44c1-b55f-bb27be7aa484" xlink:href="trs-20241231.xsd#trs_MaximumRetention"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_InsurancecoverageLineItems_72b79d85-df53-4bb4-9d9e-455350f0ef30" xlink:to="loc_trs_MaximumRetention_ff7e4496-8850-44c1-b55f-bb27be7aa484" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_StopLossLimit_2b5f6f58-2827-4413-9b3e-2fd77827d04a" xlink:href="trs-20241231.xsd#trs_StopLossLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_InsurancecoverageLineItems_72b79d85-df53-4bb4-9d9e-455350f0ef30" xlink:to="loc_trs_StopLossLimit_2b5f6f58-2827-4413-9b3e-2fd77827d04a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/SummaryofSignificantAccountingPoliciesForeignCurrencyTranslationDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#SummaryofSignificantAccountingPoliciesForeignCurrencyTranslationDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SummaryofSignificantAccountingPoliciesForeignCurrencyTranslationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_trs_ForeignCurrencyTranslationLineItems_967771cb-c366-42fb-b35f-432f8c7fdf9c" xlink:href="trs-20241231.xsd#trs_ForeignCurrencyTranslationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ForeignCurrencyTranslationTable_3570fc8a-6402-4807-b63a-09ae19e031fb" xlink:href="trs-20241231.xsd#trs_ForeignCurrencyTranslationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_trs_ForeignCurrencyTranslationLineItems_967771cb-c366-42fb-b35f-432f8c7fdf9c" xlink:to="loc_trs_ForeignCurrencyTranslationTable_3570fc8a-6402-4807-b63a-09ae19e031fb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_ac982226-0d6c-49f8-ae58-2a308f0e01c9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ForeignCurrencyTranslationTable_3570fc8a-6402-4807-b63a-09ae19e031fb" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_ac982226-0d6c-49f8-ae58-2a308f0e01c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_ac982226-0d6c-49f8-ae58-2a308f0e01c9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_ac982226-0d6c-49f8-ae58-2a308f0e01c9" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_ac982226-0d6c-49f8-ae58-2a308f0e01c9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_ebe2d817-ffd4-46ba-bc9b-dde503adad76" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_ac982226-0d6c-49f8-ae58-2a308f0e01c9" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_ebe2d817-ffd4-46ba-bc9b-dde503adad76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherExpenseMember_ed961e51-e064-4d1f-8869-e21911a0b8eb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_ebe2d817-ffd4-46ba-bc9b-dde503adad76" xlink:to="loc_us-gaap_OtherExpenseMember_ed961e51-e064-4d1f-8869-e21911a0b8eb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossRealized_1236dd0f-85c7-45be-92ed-6452a8364158" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignCurrencyTransactionGainLossRealized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_ForeignCurrencyTranslationLineItems_967771cb-c366-42fb-b35f-432f8c7fdf9c" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossRealized_1236dd0f-85c7-45be-92ed-6452a8364158" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EquityOfferingDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EquityOfferingDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EquityOfferingDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_trs_EquityOfferingLineItems_fd46c505-6d3b-4f71-bfd8-a58575f8c376" xlink:href="trs-20241231.xsd#trs_EquityOfferingLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ScheduleOfEquityOfferingTable_33a4dccd-5702-4001-a354-7dc5a0345fc6" xlink:href="trs-20241231.xsd#trs_ScheduleOfEquityOfferingTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_trs_EquityOfferingLineItems_fd46c505-6d3b-4f71-bfd8-a58575f8c376" xlink:to="loc_trs_ScheduleOfEquityOfferingTable_33a4dccd-5702-4001-a354-7dc5a0345fc6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_736db4c1-30ab-45a5-8400-27c8ed1c3a3e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfEquityOfferingTable_33a4dccd-5702-4001-a354-7dc5a0345fc6" xlink:to="loc_us-gaap_StatementClassOfStockAxis_736db4c1-30ab-45a5-8400-27c8ed1c3a3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_736db4c1-30ab-45a5-8400-27c8ed1c3a3e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_736db4c1-30ab-45a5-8400-27c8ed1c3a3e" xlink:to="loc_us-gaap_ClassOfStockDomain_736db4c1-30ab-45a5-8400-27c8ed1c3a3e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_032b8f58-3c99-4e47-acf6-1fc47b9a4d56" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_736db4c1-30ab-45a5-8400-27c8ed1c3a3e" xlink:to="loc_us-gaap_ClassOfStockDomain_032b8f58-3c99-4e47-acf6-1fc47b9a4d56" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_d29a9597-ab13-4843-80bc-eb154c0a61ac" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_032b8f58-3c99-4e47-acf6-1fc47b9a4d56" xlink:to="loc_us-gaap_CommonStockMember_d29a9597-ab13-4843-80bc-eb154c0a61ac" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_7b999bfe-2ceb-4c30-b98c-709268ce2cb2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_EquityOfferingLineItems_fd46c505-6d3b-4f71-bfd8-a58575f8c376" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_7b999bfe-2ceb-4c30-b98c-709268ce2cb2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_StockIssuedDuringPeriodValuePerShareOfferingPrice_0774524b-a5b9-474b-8728-258802957586" xlink:href="trs-20241231.xsd#trs_StockIssuedDuringPeriodValuePerShareOfferingPrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_EquityOfferingLineItems_fd46c505-6d3b-4f71-bfd8-a58575f8c376" xlink:to="loc_trs_StockIssuedDuringPeriodValuePerShareOfferingPrice_0774524b-a5b9-474b-8728-258802957586" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_69ed1d8b-9715-4a85-8059-b8da3f0d030b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_EquityOfferingLineItems_fd46c505-6d3b-4f71-bfd8-a58575f8c376" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts_69ed1d8b-9715-4a85-8059-b8da3f0d030b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_d9201236-f6b7-4f29-8e61-0a72d5fba1aa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_EquityOfferingLineItems_fd46c505-6d3b-4f71-bfd8-a58575f8c376" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_d9201236-f6b7-4f29-8e61-0a72d5fba1aa" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/AcquisitionsAcquisitionsNarrativeDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#AcquisitionsAcquisitionsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/AcquisitionsAcquisitionsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_cf2643fb-8cd8-4885-b8c5-d5546da476d8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_cf2643fb-8cd8-4885-b8c5-d5546da476d8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_8ca0978b-745a-46a2-81b8-0283b07d270f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_cf2643fb-8cd8-4885-b8c5-d5546da476d8" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_8ca0978b-745a-46a2-81b8-0283b07d270f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_8ca0978b-745a-46a2-81b8-0283b07d270f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_8ca0978b-745a-46a2-81b8-0283b07d270f" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_8ca0978b-745a-46a2-81b8-0283b07d270f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_d0935179-7bb2-4f1f-8e11-157aaa2c8713" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_8ca0978b-745a-46a2-81b8-0283b07d270f" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_d0935179-7bb2-4f1f-8e11-157aaa2c8713" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_cdd1cb00-9a63-49b5-a7dc-dde5e487af7b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_d0935179-7bb2-4f1f-8e11-157aaa2c8713" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_cdd1cb00-9a63-49b5-a7dc-dde5e487af7b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_28f8bdb5-6cfc-4619-b4d0-0357383f7a95" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_d0935179-7bb2-4f1f-8e11-157aaa2c8713" xlink:to="loc_us-gaap_CostOfSalesMember_28f8bdb5-6cfc-4619-b4d0-0357383f7a95" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_5935469f-8a74-4e34-b926-4cae3cd0ef84" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_cf2643fb-8cd8-4885-b8c5-d5546da476d8" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_5935469f-8a74-4e34-b926-4cae3cd0ef84" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5935469f-8a74-4e34-b926-4cae3cd0ef84_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_5935469f-8a74-4e34-b926-4cae3cd0ef84" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5935469f-8a74-4e34-b926-4cae3cd0ef84_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7babb41d-ed01-45bf-b0c8-388ee338ba2c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_5935469f-8a74-4e34-b926-4cae3cd0ef84" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7babb41d-ed01-45bf-b0c8-388ee338ba2c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_IntertechPlasticsLLCMember_ea9227ba-a73b-4e8d-90f7-ec24cf54cf11" xlink:href="trs-20241231.xsd#trs_IntertechPlasticsLLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7babb41d-ed01-45bf-b0c8-388ee338ba2c" xlink:to="loc_trs_IntertechPlasticsLLCMember_ea9227ba-a73b-4e8d-90f7-ec24cf54cf11" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_OmegaPlasticsMember_b966e700-25f0-4b16-b938-adc39e249db8" xlink:href="trs-20241231.xsd#trs_OmegaPlasticsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7babb41d-ed01-45bf-b0c8-388ee338ba2c" xlink:to="loc_trs_OmegaPlasticsMember_b966e700-25f0-4b16-b938-adc39e249db8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_TFIAerospaceMember_d402eb2e-4692-4818-89d5-65bcf99c0105" xlink:href="trs-20241231.xsd#trs_TFIAerospaceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7babb41d-ed01-45bf-b0c8-388ee338ba2c" xlink:to="loc_trs_TFIAerospaceMember_d402eb2e-4692-4818-89d5-65bcf99c0105" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AffabaFerrariSrlMember_075c41c8-35cb-45c8-95af-97786fb7d6eb" xlink:href="trs-20241231.xsd#trs_AffabaFerrariSrlMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7babb41d-ed01-45bf-b0c8-388ee338ba2c" xlink:to="loc_trs_AffabaFerrariSrlMember_075c41c8-35cb-45c8-95af-97786fb7d6eb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_RapakMember_59a6372c-a65f-41bf-81a3-17c5d2844ce9" xlink:href="trs-20241231.xsd#trs_RapakMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7babb41d-ed01-45bf-b0c8-388ee338ba2c" xlink:to="loc_trs_RapakMember_59a6372c-a65f-41bf-81a3-17c5d2844ce9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_RSAEngineeredProductsMemberMember_d145a636-4396-4d8e-9438-8859d5c0627a" xlink:href="trs-20241231.xsd#trs_RSAEngineeredProductsMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7babb41d-ed01-45bf-b0c8-388ee338ba2c" xlink:to="loc_trs_RSAEngineeredProductsMemberMember_d145a636-4396-4d8e-9438-8859d5c0627a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_WeldmacManufacturingCompanyMember_76c7245a-d29b-4014-8667-d781d8b20895" xlink:href="trs-20241231.xsd#trs_WeldmacManufacturingCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7babb41d-ed01-45bf-b0c8-388ee338ba2c" xlink:to="loc_trs_WeldmacManufacturingCompanyMember_76c7245a-d29b-4014-8667-d781d8b20895" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AartsPackagingBVMember_0ae93392-e5d5-4b57-885d-bdc0f97cab86" xlink:href="trs-20241231.xsd#trs_AartsPackagingBVMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7babb41d-ed01-45bf-b0c8-388ee338ba2c" xlink:to="loc_trs_AartsPackagingBVMember_0ae93392-e5d5-4b57-885d-bdc0f97cab86" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_d2846aac-a59c-4a03-919f-803f0266962e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_cf2643fb-8cd8-4885-b8c5-d5546da476d8" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_d2846aac-a59c-4a03-919f-803f0266962e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_d2846aac-a59c-4a03-919f-803f0266962e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_d2846aac-a59c-4a03-919f-803f0266962e" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_d2846aac-a59c-4a03-919f-803f0266962e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_09f8bd67-686e-4fb3-b1ae-f5a6f9d6b227" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_d2846aac-a59c-4a03-919f-803f0266962e" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_09f8bd67-686e-4fb3-b1ae-f5a6f9d6b227" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_0ee321ff-8b33-4f03-a285-163ac15c8a35" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_09f8bd67-686e-4fb3-b1ae-f5a6f9d6b227" xlink:to="loc_us-gaap_SubsequentEventMember_0ee321ff-8b33-4f03-a285-163ac15c8a35" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_83d20d50-1498-4af5-bcc6-a19c9bc9694e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_83d20d50-1498-4af5-bcc6-a19c9bc9694e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_d9c59011-ef7b-4f44-8a0e-32ef6b250a85" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:to="loc_us-gaap_Revenues_d9c59011-ef7b-4f44-8a0e-32ef6b250a85" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueLow_51c09ad8-8c8e-41e0-bcc5-35a7dca6af17" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueLow"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueLow_51c09ad8-8c8e-41e0-bcc5-35a7dca6af17" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_d426fafb-90a4-4724-9d1e-dee41e9adb8f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh_d426fafb-90a4-4724-9d1e-dee41e9adb8f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_ee435527-6bc2-40d6-a9f7-1b02d91ea617" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_ee435527-6bc2-40d6-a9f7-1b02d91ea617" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_d21cd6b9-322d-4638-8bb4-f51eabfcdded" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_d21cd6b9-322d-4638-8bb4-f51eabfcdded" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities_4c82e37c-6f5f-40a3-8d84-87f49b500bd0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDeferredTaxLiabilities_4c82e37c-6f5f-40a3-8d84-87f49b500bd0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_BusinessCombinationRecognizedIdentifiableAssetsandLiabilitiesAssumedNetWorkingCapital_8a73f629-3453-48a2-a7b0-3c4103dbbfbe" xlink:href="trs-20241231.xsd#trs_BusinessCombinationRecognizedIdentifiableAssetsandLiabilitiesAssumedNetWorkingCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:to="loc_trs_BusinessCombinationRecognizedIdentifiableAssetsandLiabilitiesAssumedNetWorkingCapital_8a73f629-3453-48a2-a7b0-3c4103dbbfbe" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_ccee0502-61fd-4c0d-9d48-9522ca924015" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_ccee0502-61fd-4c0d-9d48-9522ca924015" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_f3b1a81a-6e83-4bbc-a557-a6f16b64e316" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:to="loc_us-gaap_Goodwill_f3b1a81a-6e83-4bbc-a557-a6f16b64e316" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_7dc04286-988a-455a-a2ce-a11cff400753" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1_7dc04286-988a-455a-a2ce-a11cff400753" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInTheRangeOfOutcomesContingentConsiderationLiabilityValueHigh_14821f16-5f44-4c81-b5c2-a1fad6c560d7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInTheRangeOfOutcomesContingentConsiderationLiabilityValueHigh"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInTheRangeOfOutcomesContingentConsiderationLiabilityValueHigh_14821f16-5f44-4c81-b5c2-a1fad6c560d7" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_79cc55f0-edc1-4cb5-85cd-18df03b33780" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_bba839e3-fb15-4d7f-afbf-bdc3d78a095d" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_79cc55f0-edc1-4cb5-85cd-18df03b33780" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/RealignmentActionsDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#RealignmentActionsDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/RealignmentActionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_trs_RealignmentActionsLineItems_8e98165a-1b0d-4d7b-9c7a-a8077510bc2f" xlink:href="trs-20241231.xsd#trs_RealignmentActionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_RealignmentActionsTable_30b7bb9a-8c49-41d7-b5cb-d7ffcb733760" xlink:href="trs-20241231.xsd#trs_RealignmentActionsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_trs_RealignmentActionsLineItems_8e98165a-1b0d-4d7b-9c7a-a8077510bc2f" xlink:to="loc_trs_RealignmentActionsTable_30b7bb9a-8c49-41d7-b5cb-d7ffcb733760" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_c93d6da8-4a7e-4842-a364-88184da61596" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_RealignmentActionsTable_30b7bb9a-8c49-41d7-b5cb-d7ffcb733760" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_c93d6da8-4a7e-4842-a364-88184da61596" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_c93d6da8-4a7e-4842-a364-88184da61596_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_c93d6da8-4a7e-4842-a364-88184da61596" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_c93d6da8-4a7e-4842-a364-88184da61596_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_89b7a7fc-48d6-4525-a0f0-d98e38de4a1d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_c93d6da8-4a7e-4842-a364-88184da61596" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_89b7a7fc-48d6-4525-a0f0-d98e38de4a1d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_d12863f1-79d0-4597-b501-aeb2c6b26ac1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_89b7a7fc-48d6-4525-a0f0-d98e38de4a1d" xlink:to="loc_us-gaap_CostOfSalesMember_d12863f1-79d0-4597-b501-aeb2c6b26ac1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_1eea3df0-5fe4-4b4a-840c-5c9c2262ede7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_89b7a7fc-48d6-4525-a0f0-d98e38de4a1d" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_1eea3df0-5fe4-4b4a-840c-5c9c2262ede7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_NetGainLossOnDispositionOfAssetMember_e53abd7d-1d9d-411f-a77e-054afb960059" xlink:href="trs-20241231.xsd#trs_NetGainLossOnDispositionOfAssetMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_89b7a7fc-48d6-4525-a0f0-d98e38de4a1d" xlink:to="loc_trs_NetGainLossOnDispositionOfAssetMember_e53abd7d-1d9d-411f-a77e-054afb960059" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_RealignmentActionsAxis_413646b5-3945-41a1-99d8-c266c9f29930" xlink:href="trs-20241231.xsd#trs_RealignmentActionsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_RealignmentActionsTable_30b7bb9a-8c49-41d7-b5cb-d7ffcb733760" xlink:to="loc_trs_RealignmentActionsAxis_413646b5-3945-41a1-99d8-c266c9f29930" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_RealignmentActionsDomain_413646b5-3945-41a1-99d8-c266c9f29930_default" xlink:href="trs-20241231.xsd#trs_RealignmentActionsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_RealignmentActionsAxis_413646b5-3945-41a1-99d8-c266c9f29930" xlink:to="loc_trs_RealignmentActionsDomain_413646b5-3945-41a1-99d8-c266c9f29930_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_RealignmentActionsDomain_59a63e66-1dd2-4525-ac83-eae31ab92774" xlink:href="trs-20241231.xsd#trs_RealignmentActionsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_RealignmentActionsAxis_413646b5-3945-41a1-99d8-c266c9f29930" xlink:to="loc_trs_RealignmentActionsDomain_59a63e66-1dd2-4525-ac83-eae31ab92774" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_RealignmentActionsMember_7648f44a-2ee1-419b-a58e-95390674326c" xlink:href="trs-20241231.xsd#trs_RealignmentActionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_RealignmentActionsDomain_59a63e66-1dd2-4525-ac83-eae31ab92774" xlink:to="loc_trs_RealignmentActionsMember_7648f44a-2ee1-419b-a58e-95390674326c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InventoryWriteDown_957605a3-1815-4663-a2a5-f636d607fa64" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InventoryWriteDown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_RealignmentActionsLineItems_8e98165a-1b0d-4d7b-9c7a-a8077510bc2f" xlink:to="loc_us-gaap_InventoryWriteDown_957605a3-1815-4663-a2a5-f636d607fa64" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeveranceCosts1_d28b0df0-44a9-475f-92cd-b53005f492ce" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SeveranceCosts1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_RealignmentActionsLineItems_8e98165a-1b0d-4d7b-9c7a-a8077510bc2f" xlink:to="loc_us-gaap_SeveranceCosts1_d28b0df0-44a9-475f-92cd-b53005f492ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_CashPaidForSeverance_4d53667e-7c92-4500-ae7d-95587a0f0c9e" xlink:href="trs-20241231.xsd#trs_CashPaidForSeverance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_RealignmentActionsLineItems_8e98165a-1b0d-4d7b-9c7a-a8077510bc2f" xlink:to="loc_trs_CashPaidForSeverance_4d53667e-7c92-4500-ae7d-95587a0f0c9e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ChargesRelatedToRealignmentActions_b9056133-c3a6-4ea9-bdb8-d2b9debbf512" xlink:href="trs-20241231.xsd#trs_ChargesRelatedToRealignmentActions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_RealignmentActionsLineItems_8e98165a-1b0d-4d7b-9c7a-a8077510bc2f" xlink:to="loc_trs_ChargesRelatedToRealignmentActions_b9056133-c3a6-4ea9-bdb8-d2b9debbf512" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Realignmentcosts_e85f5a21-f82a-45f9-b244-6464f082c0d2" xlink:href="trs-20241231.xsd#trs_Realignmentcosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_RealignmentActionsLineItems_8e98165a-1b0d-4d7b-9c7a-a8077510bc2f" xlink:to="loc_trs_Realignmentcosts_e85f5a21-f82a-45f9-b244-6464f082c0d2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_FacilityConsolidationRealignmentCosts_17aad04e-73d6-4b3c-be51-2013bdba231d" xlink:href="trs-20241231.xsd#trs_FacilityConsolidationRealignmentCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_RealignmentActionsLineItems_8e98165a-1b0d-4d7b-9c7a-a8077510bc2f" xlink:to="loc_trs_FacilityConsolidationRealignmentCosts_17aad04e-73d6-4b3c-be51-2013bdba231d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_EmployeeRelatedCosts_5906dda6-c73a-4491-be88-cebdb7f14a59" xlink:href="trs-20241231.xsd#trs_EmployeeRelatedCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_RealignmentActionsLineItems_8e98165a-1b0d-4d7b-9c7a-a8077510bc2f" xlink:to="loc_trs_EmployeeRelatedCosts_5906dda6-c73a-4491-be88-cebdb7f14a59" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveAcceleratedDepreciation_6dfe825b-e5c5-4a52-8aa8-bf4c38870dbf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringReserveAcceleratedDepreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_RealignmentActionsLineItems_8e98165a-1b0d-4d7b-9c7a-a8077510bc2f" xlink:to="loc_us-gaap_RestructuringReserveAcceleratedDepreciation_6dfe825b-e5c5-4a52-8aa8-bf4c38870dbf" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/RevenueDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#RevenueDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/RevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_187bc356-ee1e-4ec9-82bf-82d6d77d5653" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_07a0e6ea-8b46-430d-8bcc-a3d7f64f947f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_187bc356-ee1e-4ec9-82bf-82d6d77d5653" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_07a0e6ea-8b46-430d-8bcc-a3d7f64f947f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_6cd202c5-ba5d-490d-94e8-3b1bf7c16696" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_07a0e6ea-8b46-430d-8bcc-a3d7f64f947f" xlink:to="loc_srt_MajorCustomersAxis_6cd202c5-ba5d-490d-94e8-3b1bf7c16696" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_6cd202c5-ba5d-490d-94e8-3b1bf7c16696_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_6cd202c5-ba5d-490d-94e8-3b1bf7c16696" xlink:to="loc_srt_NameOfMajorCustomerDomain_6cd202c5-ba5d-490d-94e8-3b1bf7c16696_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_00cca3ac-edec-460b-b231-de2264100720" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_6cd202c5-ba5d-490d-94e8-3b1bf7c16696" xlink:to="loc_srt_NameOfMajorCustomerDomain_00cca3ac-edec-460b-b231-de2264100720" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ConsumerendmarketcustomersMember_943c6fef-1d16-4b2e-84a1-f069202adcb9" xlink:href="trs-20241231.xsd#trs_ConsumerendmarketcustomersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_00cca3ac-edec-460b-b231-de2264100720" xlink:to="loc_trs_ConsumerendmarketcustomersMember_943c6fef-1d16-4b2e-84a1-f069202adcb9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AerospaceendmarketcustomersMember_7fac1722-dcc8-4261-bffe-033ac1f2475c" xlink:href="trs-20241231.xsd#trs_AerospaceendmarketcustomersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_00cca3ac-edec-460b-b231-de2264100720" xlink:to="loc_trs_AerospaceendmarketcustomersMember_7fac1722-dcc8-4261-bffe-033ac1f2475c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_IndustrialendmarketcustomersMember_5caf560f-4bcb-4562-8592-659beb5627dd" xlink:href="trs-20241231.xsd#trs_IndustrialendmarketcustomersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_00cca3ac-edec-460b-b231-de2264100720" xlink:to="loc_trs_IndustrialendmarketcustomersMember_5caf560f-4bcb-4562-8592-659beb5627dd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_OilandgascustomerendmarketMember_af7f3dd4-946b-42ba-b996-6d23b48da4b5" xlink:href="trs-20241231.xsd#trs_OilandgascustomerendmarketMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_00cca3ac-edec-460b-b231-de2264100720" xlink:to="loc_trs_OilandgascustomerendmarketMember_af7f3dd4-946b-42ba-b996-6d23b48da4b5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_3135c031-0dab-426f-8572-91f339d30aff" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_187bc356-ee1e-4ec9-82bf-82d6d77d5653" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_3135c031-0dab-426f-8572-91f339d30aff" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/GoodwillandOtherIntangibleAssetsGoodwillNarrativeDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#GoodwillandOtherIntangibleAssetsGoodwillNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/GoodwillandOtherIntangibleAssetsGoodwillNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_1feaaaeb-29d2-47ec-945a-145b57a31b4d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_1feaaaeb-29d2-47ec-945a-145b57a31b4d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_469edf6b-5a74-4836-8b10-f16f4b1630bc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_1feaaaeb-29d2-47ec-945a-145b57a31b4d" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_469edf6b-5a74-4836-8b10-f16f4b1630bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_469edf6b-5a74-4836-8b10-f16f4b1630bc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_469edf6b-5a74-4836-8b10-f16f4b1630bc" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_469edf6b-5a74-4836-8b10-f16f4b1630bc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_5076c10d-cdcb-4f4e-aa96-66275ba064a9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_469edf6b-5a74-4836-8b10-f16f4b1630bc" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_5076c10d-cdcb-4f4e-aa96-66275ba064a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputLongTermRevenueGrowthRateMember_08a92f32-59f2-4632-99e2-ad82e20e4f6a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputLongTermRevenueGrowthRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_5076c10d-cdcb-4f4e-aa96-66275ba064a9" xlink:to="loc_us-gaap_MeasurementInputLongTermRevenueGrowthRateMember_08a92f32-59f2-4632-99e2-ad82e20e4f6a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputDiscountRateMember_9f2cfb39-59fc-4e1a-86b6-1ee595a46fc0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputDiscountRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_5076c10d-cdcb-4f4e-aa96-66275ba064a9" xlink:to="loc_us-gaap_MeasurementInputDiscountRateMember_9f2cfb39-59fc-4e1a-86b6-1ee595a46fc0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_QuantitativeImpairmentTestAxis_2cb098b2-a630-43bd-964d-2211c631a3ee" xlink:href="trs-20241231.xsd#trs_QuantitativeImpairmentTestAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_1feaaaeb-29d2-47ec-945a-145b57a31b4d" xlink:to="loc_trs_QuantitativeImpairmentTestAxis_2cb098b2-a630-43bd-964d-2211c631a3ee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ImpairmentTestDomain_2cb098b2-a630-43bd-964d-2211c631a3ee_default" xlink:href="trs-20241231.xsd#trs_ImpairmentTestDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_QuantitativeImpairmentTestAxis_2cb098b2-a630-43bd-964d-2211c631a3ee" xlink:to="loc_trs_ImpairmentTestDomain_2cb098b2-a630-43bd-964d-2211c631a3ee_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ImpairmentTestDomain_8908094d-bcf6-4437-9a47-3bcdb5656eaf" xlink:href="trs-20241231.xsd#trs_ImpairmentTestDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_QuantitativeImpairmentTestAxis_2cb098b2-a630-43bd-964d-2211c631a3ee" xlink:to="loc_trs_ImpairmentTestDomain_8908094d-bcf6-4437-9a47-3bcdb5656eaf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillMember_8fc4166d-68a7-4dcd-82e8-f1b53da7f0bb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_ImpairmentTestDomain_8908094d-bcf6-4437-9a47-3bcdb5656eaf" xlink:to="loc_us-gaap_GoodwillMember_8fc4166d-68a7-4dcd-82e8-f1b53da7f0bb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReportingUnitAxis_a333bc91-694c-4a61-8729-e08883500e21" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ReportingUnitAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_1feaaaeb-29d2-47ec-945a-145b57a31b4d" xlink:to="loc_us-gaap_ReportingUnitAxis_a333bc91-694c-4a61-8729-e08883500e21" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReportingUnitDomain_a333bc91-694c-4a61-8729-e08883500e21_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ReportingUnitDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReportingUnitAxis_a333bc91-694c-4a61-8729-e08883500e21" xlink:to="loc_us-gaap_ReportingUnitDomain_a333bc91-694c-4a61-8729-e08883500e21_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReportingUnitDomain_d423a2d9-62ba-4060-954d-4a01a4916c3b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ReportingUnitDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReportingUnitAxis_a333bc91-694c-4a61-8729-e08883500e21" xlink:to="loc_us-gaap_ReportingUnitDomain_d423a2d9-62ba-4060-954d-4a01a4916c3b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AerospaceReportingUnitMember_28c132a6-3d12-4abb-9080-3bf95505d7ec" xlink:href="trs-20241231.xsd#trs_AerospaceReportingUnitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReportingUnitDomain_d423a2d9-62ba-4060-954d-4a01a4916c3b" xlink:to="loc_trs_AerospaceReportingUnitMember_28c132a6-3d12-4abb-9080-3bf95505d7ec" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_MachinedProductsReportingUnitMember_dfa38ffc-70eb-497a-8efe-dcd9c31f5962" xlink:href="trs-20241231.xsd#trs_MachinedProductsReportingUnitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReportingUnitDomain_d423a2d9-62ba-4060-954d-4a01a4916c3b" xlink:to="loc_trs_MachinedProductsReportingUnitMember_dfa38ffc-70eb-497a-8efe-dcd9c31f5962" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AerospaceFastenersReportingUnitMember_fab7ea27-2e9d-4e31-a403-06b75f1c281e" xlink:href="trs-20241231.xsd#trs_AerospaceFastenersReportingUnitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReportingUnitDomain_d423a2d9-62ba-4060-954d-4a01a4916c3b" xlink:to="loc_trs_AerospaceFastenersReportingUnitMember_fab7ea27-2e9d-4e31-a403-06b75f1c281e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AerospaceEngineeredProductsReportingUnitMember_a0b1800f-dff9-43cd-81c4-dda4645ba6b6" xlink:href="trs-20241231.xsd#trs_AerospaceEngineeredProductsReportingUnitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReportingUnitDomain_d423a2d9-62ba-4060-954d-4a01a4916c3b" xlink:to="loc_trs_AerospaceEngineeredProductsReportingUnitMember_a0b1800f-dff9-43cd-81c4-dda4645ba6b6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_ed93bd6c-6ccb-4b5b-8074-10a1fdfadcda" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_1feaaaeb-29d2-47ec-945a-145b57a31b4d" xlink:to="loc_srt_RangeAxis_ed93bd6c-6ccb-4b5b-8074-10a1fdfadcda" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_ed93bd6c-6ccb-4b5b-8074-10a1fdfadcda_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_ed93bd6c-6ccb-4b5b-8074-10a1fdfadcda" xlink:to="loc_srt_RangeMember_ed93bd6c-6ccb-4b5b-8074-10a1fdfadcda_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_efe0356e-b731-4224-9993-e74f2fae337d" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_ed93bd6c-6ccb-4b5b-8074-10a1fdfadcda" xlink:to="loc_srt_RangeMember_efe0356e-b731-4224-9993-e74f2fae337d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_c623de52-1636-4a39-a9c0-e698db5b42c0" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_efe0356e-b731-4224-9993-e74f2fae337d" xlink:to="loc_srt_MaximumMember_c623de52-1636-4a39-a9c0-e698db5b42c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_10c8b505-3981-41fe-9274-93b8f89a28e7" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_efe0356e-b731-4224-9993-e74f2fae337d" xlink:to="loc_srt_MinimumMember_10c8b505-3981-41fe-9274-93b8f89a28e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_d4885f72-8881-40d8-bba7-fb016fab3ab8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_1feaaaeb-29d2-47ec-945a-145b57a31b4d" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_d4885f72-8881-40d8-bba7-fb016fab3ab8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_d4885f72-8881-40d8-bba7-fb016fab3ab8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_d4885f72-8881-40d8-bba7-fb016fab3ab8" xlink:to="loc_us-gaap_SegmentDomain_d4885f72-8881-40d8-bba7-fb016fab3ab8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_83fcccb5-b8af-48a5-b2b6-464d091db2eb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_d4885f72-8881-40d8-bba7-fb016fab3ab8" xlink:to="loc_us-gaap_SegmentDomain_83fcccb5-b8af-48a5-b2b6-464d091db2eb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AerospaceReportableSegmentMember_08f911de-9017-4838-8355-db15454fad56" xlink:href="trs-20241231.xsd#trs_AerospaceReportableSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_83fcccb5-b8af-48a5-b2b6-464d091db2eb" xlink:to="loc_trs_AerospaceReportableSegmentMember_08f911de-9017-4838-8355-db15454fad56" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_1ef13831-f0d8-4429-83a2-3211087b5bea" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_1ef13831-f0d8-4429-83a2-3211087b5bea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_9d5bcd6f-6d54-49e5-9c7d-6b9e2a9ff5c3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:to="loc_us-gaap_Goodwill_9d5bcd6f-6d54-49e5-9c7d-6b9e2a9ff5c3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount_d1a2e63c-e627-495c-bbf2-d9cbdb36cc05" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:to="loc_us-gaap_ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount_d1a2e63c-e627-495c-bbf2-d9cbdb36cc05" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Fairvalueinputsvaluationmethodresidualgrowthrate_191654c8-714c-4fb3-80e2-c2ddcf970fb9" xlink:href="trs-20241231.xsd#trs_Fairvalueinputsvaluationmethodresidualgrowthrate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:to="loc_trs_Fairvalueinputsvaluationmethodresidualgrowthrate_191654c8-714c-4fb3-80e2-c2ddcf970fb9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_FairValueInputsValuationMethodWeightingPercentageUsedIncomeBasedApproach_cc6fa864-1616-4c7f-91d0-12689f497ebd" xlink:href="trs-20241231.xsd#trs_FairValueInputsValuationMethodWeightingPercentageUsedIncomeBasedApproach"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:to="loc_trs_FairValueInputsValuationMethodWeightingPercentageUsedIncomeBasedApproach_cc6fa864-1616-4c7f-91d0-12689f497ebd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Fairvalueinputsvaluationmethoddiscountrate_d5362c7a-330f-4e8b-84f0-f00ebda07f50" xlink:href="trs-20241231.xsd#trs_Fairvalueinputsvaluationmethoddiscountrate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:to="loc_trs_Fairvalueinputsvaluationmethoddiscountrate_d5362c7a-330f-4e8b-84f0-f00ebda07f50" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_FairValueInputsValuationMethodWeightingPercentageUsedMarketBasedApproach_651d9427-670e-498c-ab97-568308a7f8cd" xlink:href="trs-20241231.xsd#trs_FairValueInputsValuationMethodWeightingPercentageUsedMarketBasedApproach"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:to="loc_trs_FairValueInputsValuationMethodWeightingPercentageUsedMarketBasedApproach_651d9427-670e-498c-ab97-568308a7f8cd" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ChangeInDiscountRate_4ecf4c2d-ae84-453f-9f82-07685e96af2c" xlink:href="trs-20241231.xsd#trs_ChangeInDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:to="loc_trs_ChangeInDiscountRate_4ecf4c2d-ae84-453f-9f82-07685e96af2c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ChangeInGoodwillImpairmentDueToChangeInDiscountRate_3351777d-cc40-4092-873c-6689692e5f03" xlink:href="trs-20241231.xsd#trs_ChangeInGoodwillImpairmentDueToChangeInDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:to="loc_trs_ChangeInGoodwillImpairmentDueToChangeInDiscountRate_3351777d-cc40-4092-873c-6689692e5f03" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ChangeInTerminalGrowthRate_5b3bc32e-0f0a-44a6-aad1-7288c4f63a97" xlink:href="trs-20241231.xsd#trs_ChangeInTerminalGrowthRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:to="loc_trs_ChangeInTerminalGrowthRate_5b3bc32e-0f0a-44a6-aad1-7288c4f63a97" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ChangeInGoodwillImpairmentDueToChangeInTerminalRate_f7c3698c-9ec5-4a19-9ed2-427f22252f6d" xlink:href="trs-20241231.xsd#trs_ChangeInGoodwillImpairmentDueToChangeInTerminalRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:to="loc_trs_ChangeInGoodwillImpairmentDueToChangeInTerminalRate_f7c3698c-9ec5-4a19-9ed2-427f22252f6d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_SensitivityAnalysisOfImpairmentImpactOfChangeInTerminalGrowthRate_5a44c5c2-6f94-40b3-b656-ab2295ec6cf8" xlink:href="trs-20241231.xsd#trs_SensitivityAnalysisOfImpairmentImpactOfChangeInTerminalGrowthRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:to="loc_trs_SensitivityAnalysisOfImpairmentImpactOfChangeInTerminalGrowthRate_5a44c5c2-6f94-40b3-b656-ab2295ec6cf8" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_SensitivityAnalysisOfImpairmentImpactOfChangeInWACC_086d1b63-26ae-496d-9b78-48e91ba169f6" xlink:href="trs-20241231.xsd#trs_SensitivityAnalysisOfImpairmentImpactOfChangeInWACC"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_6c394b34-3fa6-42f2-b3ce-d36d73085cd8" xlink:to="loc_trs_SensitivityAnalysisOfImpairmentImpactOfChangeInWACC_086d1b63-26ae-496d-9b78-48e91ba169f6" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/GoodwillandOtherIntangibleAssetsGoodwillRollforwardDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#GoodwillandOtherIntangibleAssetsGoodwillRollforwardDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/GoodwillandOtherIntangibleAssetsGoodwillRollforwardDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_32960beb-f1cb-484f-8ba1-2707ead92578" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_ed9b0ae6-ca22-480e-8fcd-d18503d1ade1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_32960beb-f1cb-484f-8ba1-2707ead92578" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_ed9b0ae6-ca22-480e-8fcd-d18503d1ade1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_a6e624b7-4065-4741-a4fa-f5be9e8ff7bc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_ed9b0ae6-ca22-480e-8fcd-d18503d1ade1" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_a6e624b7-4065-4741-a4fa-f5be9e8ff7bc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_a6e624b7-4065-4741-a4fa-f5be9e8ff7bc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_a6e624b7-4065-4741-a4fa-f5be9e8ff7bc" xlink:to="loc_us-gaap_SegmentDomain_a6e624b7-4065-4741-a4fa-f5be9e8ff7bc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_5b1cc0ff-b4f8-4ebc-af12-d00e848a982e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_a6e624b7-4065-4741-a4fa-f5be9e8ff7bc" xlink:to="loc_us-gaap_SegmentDomain_5b1cc0ff-b4f8-4ebc-af12-d00e848a982e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_PackagingReportableSegmentMember_aaa1b22f-bf62-47df-87f9-0acb02d65c9a" xlink:href="trs-20241231.xsd#trs_PackagingReportableSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5b1cc0ff-b4f8-4ebc-af12-d00e848a982e" xlink:to="loc_trs_PackagingReportableSegmentMember_aaa1b22f-bf62-47df-87f9-0acb02d65c9a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AerospaceReportableSegmentMember_3d9258ce-29ba-46ea-8c5b-e5e290e275b9" xlink:href="trs-20241231.xsd#trs_AerospaceReportableSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5b1cc0ff-b4f8-4ebc-af12-d00e848a982e" xlink:to="loc_trs_AerospaceReportableSegmentMember_3d9258ce-29ba-46ea-8c5b-e5e290e275b9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_SpecialtyProductsReportableSegmentMember_c2f369a0-150d-480d-9fc0-3ff860b77c05" xlink:href="trs-20241231.xsd#trs_SpecialtyProductsReportableSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_5b1cc0ff-b4f8-4ebc-af12-d00e848a982e" xlink:to="loc_trs_SpecialtyProductsReportableSegmentMember_c2f369a0-150d-480d-9fc0-3ff860b77c05" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_d8f22869-975a-49e8-9ffd-1361a178486d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_32960beb-f1cb-484f-8ba1-2707ead92578" xlink:to="loc_us-gaap_GoodwillRollForward_d8f22869-975a-49e8-9ffd-1361a178486d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_1c338973-4288-4ae3-a50b-184473485d4c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_d8f22869-975a-49e8-9ffd-1361a178486d" xlink:to="loc_us-gaap_Goodwill_1c338973-4288-4ae3-a50b-184473485d4c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_6a9e9d17-78f8-4eae-9945-ce70633372aa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_d8f22869-975a-49e8-9ffd-1361a178486d" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_6a9e9d17-78f8-4eae-9945-ce70633372aa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_e0f8382c-ee66-43d8-8a83-1529bb9e385e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_d8f22869-975a-49e8-9ffd-1361a178486d" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_e0f8382c-ee66-43d8-8a83-1529bb9e385e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Goodwillreassignedbetweensegments_52c898c2-21bb-4ab3-8bad-52739f9e4a9d" xlink:href="trs-20241231.xsd#trs_Goodwillreassignedbetweensegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_d8f22869-975a-49e8-9ffd-1361a178486d" xlink:to="loc_trs_Goodwillreassignedbetweensegments_52c898c2-21bb-4ab3-8bad-52739f9e4a9d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_71b3000a-66ee-40b8-b948-0e1178b4c4de" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_d8f22869-975a-49e8-9ffd-1361a178486d" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_71b3000a-66ee-40b8-b948-0e1178b4c4de" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_8285f131-15a2-4348-aa64-7ad06cef17e7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Goodwill"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/GoodwillandOtherIntangibleAssetsIntangiblesNarrativeDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#GoodwillandOtherIntangibleAssetsIntangiblesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/GoodwillandOtherIntangibleAssetsIntangiblesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_069d7f6d-7d0f-4de6-9a0d-d7d6242a2fbf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_c9eb2faf-3d00-44b9-9a51-a8f758c5a869" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_069d7f6d-7d0f-4de6-9a0d-d7d6242a2fbf" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_c9eb2faf-3d00-44b9-9a51-a8f758c5a869" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeAxis_9ecb9e6f-2d73-4216-9dbb-4b8fd479bdd5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_c9eb2faf-3d00-44b9-9a51-a8f758c5a869" xlink:to="loc_us-gaap_MeasurementInputTypeAxis_9ecb9e6f-2d73-4216-9dbb-4b8fd479bdd5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_9ecb9e6f-2d73-4216-9dbb-4b8fd479bdd5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_9ecb9e6f-2d73-4216-9dbb-4b8fd479bdd5" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_9ecb9e6f-2d73-4216-9dbb-4b8fd479bdd5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputTypeDomain_26579e07-9859-48f5-b85c-f8b1bc5c4e19" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_MeasurementInputTypeAxis_9ecb9e6f-2d73-4216-9dbb-4b8fd479bdd5" xlink:to="loc_us-gaap_MeasurementInputTypeDomain_26579e07-9859-48f5-b85c-f8b1bc5c4e19" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputLongTermRevenueGrowthRateMember_1aa93801-0452-471a-8a4f-7b6b4863519e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputLongTermRevenueGrowthRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_26579e07-9859-48f5-b85c-f8b1bc5c4e19" xlink:to="loc_us-gaap_MeasurementInputLongTermRevenueGrowthRateMember_1aa93801-0452-471a-8a4f-7b6b4863519e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MeasurementInputDiscountRateMember_5cdaba26-991b-4581-aa87-99f63065fed5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MeasurementInputDiscountRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MeasurementInputTypeDomain_26579e07-9859-48f5-b85c-f8b1bc5c4e19" xlink:to="loc_us-gaap_MeasurementInputDiscountRateMember_5cdaba26-991b-4581-aa87-99f63065fed5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_619343dc-17d9-488b-8434-db9da6540ffd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_c9eb2faf-3d00-44b9-9a51-a8f758c5a869" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_619343dc-17d9-488b-8434-db9da6540ffd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_619343dc-17d9-488b-8434-db9da6540ffd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_619343dc-17d9-488b-8434-db9da6540ffd" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_619343dc-17d9-488b-8434-db9da6540ffd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5ea21f8a-fd0a-4bf6-85af-2c0c9c9d60ae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_619343dc-17d9-488b-8434-db9da6540ffd" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5ea21f8a-fd0a-4bf6-85af-2c0c9c9d60ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_abb650dd-4ce5-4fcb-9e98-f26c9c88a4ae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TrademarksAndTradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5ea21f8a-fd0a-4bf6-85af-2c0c9c9d60ae" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_abb650dd-4ce5-4fcb-9e98-f26c9c88a4ae" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_87003217-c1a3-4151-b3ca-18830bd6e0cb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_5ea21f8a-fd0a-4bf6-85af-2c0c9c9d60ae" xlink:to="loc_us-gaap_TradeNamesMember_87003217-c1a3-4151-b3ca-18830bd6e0cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_715d890f-79f6-4290-b9de-b38d2f5bf051" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_c9eb2faf-3d00-44b9-9a51-a8f758c5a869" xlink:to="loc_srt_RangeAxis_715d890f-79f6-4290-b9de-b38d2f5bf051" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_715d890f-79f6-4290-b9de-b38d2f5bf051_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_715d890f-79f6-4290-b9de-b38d2f5bf051" xlink:to="loc_srt_RangeMember_715d890f-79f6-4290-b9de-b38d2f5bf051_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_bc0a81f1-3e63-4a9b-bdda-384c25e789e4" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_715d890f-79f6-4290-b9de-b38d2f5bf051" xlink:to="loc_srt_RangeMember_bc0a81f1-3e63-4a9b-bdda-384c25e789e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_94c4e338-020d-494c-9b96-704b9b72fa36" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_bc0a81f1-3e63-4a9b-bdda-384c25e789e4" xlink:to="loc_srt_MinimumMember_94c4e338-020d-494c-9b96-704b9b72fa36" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_418dadd1-cc41-4eb4-b249-01a78bc2d0d2" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_bc0a81f1-3e63-4a9b-bdda-384c25e789e4" xlink:to="loc_srt_MaximumMember_418dadd1-cc41-4eb4-b249-01a78bc2d0d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_03c09d1d-1f67-4954-a570-99a8cc22c966" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_c9eb2faf-3d00-44b9-9a51-a8f758c5a869" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_03c09d1d-1f67-4954-a570-99a8cc22c966" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_03c09d1d-1f67-4954-a570-99a8cc22c966_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_03c09d1d-1f67-4954-a570-99a8cc22c966" xlink:to="loc_us-gaap_SegmentDomain_03c09d1d-1f67-4954-a570-99a8cc22c966_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_35c13ac7-373b-47bd-a56d-ccb99ef89df9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_03c09d1d-1f67-4954-a570-99a8cc22c966" xlink:to="loc_us-gaap_SegmentDomain_35c13ac7-373b-47bd-a56d-ccb99ef89df9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AerospaceReportableSegmentMember_58a8d122-8042-4c6d-863c-bf2d2549c550" xlink:href="trs-20241231.xsd#trs_AerospaceReportableSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_35c13ac7-373b-47bd-a56d-ccb99ef89df9" xlink:to="loc_trs_AerospaceReportableSegmentMember_58a8d122-8042-4c6d-863c-bf2d2549c550" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Fairvalueinputsvaluationmethoddiscountrate_52132598-1d06-402f-baf7-b1e3c0643f6b" xlink:href="trs-20241231.xsd#trs_Fairvalueinputsvaluationmethoddiscountrate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_069d7f6d-7d0f-4de6-9a0d-d7d6242a2fbf" xlink:to="loc_trs_Fairvalueinputsvaluationmethoddiscountrate_52132598-1d06-402f-baf7-b1e3c0643f6b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetIndefiniteLivedExcludingGoodwillStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_41051198-283c-47ee-bce4-636f2c3db6d0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ImpairmentOfIntangibleAssetIndefiniteLivedExcludingGoodwillStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_069d7f6d-7d0f-4de6-9a0d-d7d6242a2fbf" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetIndefiniteLivedExcludingGoodwillStatementOfIncomeOrComprehensiveIncomeExtensibleEnumeration_41051198-283c-47ee-bce4-636f2c3db6d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill_a18d1ae6-df0a-4c0b-bc6a-fdaaa841437c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_069d7f6d-7d0f-4de6-9a0d-d7d6242a2fbf" xlink:to="loc_us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill_a18d1ae6-df0a-4c0b-bc6a-fdaaa841437c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Fairvalueinputsvaluationmethodresidualgrowthrate_758bef1c-585e-4b9f-b375-fbea3cd4e161" xlink:href="trs-20241231.xsd#trs_Fairvalueinputsvaluationmethodresidualgrowthrate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_069d7f6d-7d0f-4de6-9a0d-d7d6242a2fbf" xlink:to="loc_trs_Fairvalueinputsvaluationmethodresidualgrowthrate_758bef1c-585e-4b9f-b375-fbea3cd4e161" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Tradenamesfairvalueexceedscarryingvaluepercentage_3f63ab2d-3f57-4213-adab-d555de74aa72" xlink:href="trs-20241231.xsd#trs_Tradenamesfairvalueexceedscarryingvaluepercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_069d7f6d-7d0f-4de6-9a0d-d7d6242a2fbf" xlink:to="loc_trs_Tradenamesfairvalueexceedscarryingvaluepercentage_3f63ab2d-3f57-4213-adab-d555de74aa72" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetImpairment_1496e945-0f2d-431f-9ff1-e8e7838db4ca" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillAndIntangibleAssetImpairment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassLineItems_069d7f6d-7d0f-4de6-9a0d-d7d6242a2fbf" xlink:to="loc_us-gaap_GoodwillAndIntangibleAssetImpairment_1496e945-0f2d-431f-9ff1-e8e7838db4ca" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/GoodwillandOtherIntangibleAssetsOtherIntangibleAssetsDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#GoodwillandOtherIntangibleAssetsOtherIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/GoodwillandOtherIntangibleAssetsOtherIntangibleAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_trs_IntangibleAssetsExcludingGoodwillLineItems_cf185ec7-0c54-4e32-bcab-ccf31ba82cf9" xlink:href="trs-20241231.xsd#trs_IntangibleAssetsExcludingGoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassTable_c38f519b-d1df-4de9-ba0e-deb77216228a" xlink:href="trs-20241231.xsd#trs_ScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_trs_IntangibleAssetsExcludingGoodwillLineItems_cf185ec7-0c54-4e32-bcab-ccf31ba82cf9" xlink:to="loc_trs_ScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassTable_c38f519b-d1df-4de9-ba0e-deb77216228a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_40acd0e6-7ab0-4fb5-8ee3-2b32028eee43" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassTable_c38f519b-d1df-4de9-ba0e-deb77216228a" xlink:to="loc_srt_RangeAxis_40acd0e6-7ab0-4fb5-8ee3-2b32028eee43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_40acd0e6-7ab0-4fb5-8ee3-2b32028eee43_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_40acd0e6-7ab0-4fb5-8ee3-2b32028eee43" xlink:to="loc_srt_RangeMember_40acd0e6-7ab0-4fb5-8ee3-2b32028eee43_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_db893b9f-0e83-423a-b6de-f455b73b4e93" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_40acd0e6-7ab0-4fb5-8ee3-2b32028eee43" xlink:to="loc_srt_RangeMember_db893b9f-0e83-423a-b6de-f455b73b4e93" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_96a6d11a-c285-4bc2-843f-0fbba46848cf" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_db893b9f-0e83-423a-b6de-f455b73b4e93" xlink:to="loc_srt_MinimumMember_96a6d11a-c285-4bc2-843f-0fbba46848cf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_2423caf9-d144-49e9-9777-64bf831be79d" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_db893b9f-0e83-423a-b6de-f455b73b4e93" xlink:to="loc_srt_MaximumMember_2423caf9-d144-49e9-9777-64bf831be79d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeAxis_41bc9fe6-1ccb-4b13-903a-a3a5b0d4b5c1" xlink:href="trs-20241231.xsd#trs_FiniteLivedIntangibleAssetsByUsefulLifeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassTable_c38f519b-d1df-4de9-ba0e-deb77216228a" xlink:to="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeAxis_41bc9fe6-1ccb-4b13-903a-a3a5b0d4b5c1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_41bc9fe6-1ccb-4b13-903a-a3a5b0d4b5c1_default" xlink:href="trs-20241231.xsd#trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeAxis_41bc9fe6-1ccb-4b13-903a-a3a5b0d4b5c1" xlink:to="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_41bc9fe6-1ccb-4b13-903a-a3a5b0d4b5c1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_82929b10-b69b-4115-9b14-1799fbd576fe" xlink:href="trs-20241231.xsd#trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeAxis_41bc9fe6-1ccb-4b13-903a-a3a5b0d4b5c1" xlink:to="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_82929b10-b69b-4115-9b14-1799fbd576fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_UsefulLifeFiveToTwelveYearsMember_34cd3706-1558-4bfe-a1cb-efdc26fed075" xlink:href="trs-20241231.xsd#trs_UsefulLifeFiveToTwelveYearsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_82929b10-b69b-4115-9b14-1799fbd576fe" xlink:to="loc_trs_UsefulLifeFiveToTwelveYearsMember_34cd3706-1558-4bfe-a1cb-efdc26fed075" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_UsefulLifeFifteenToTwentyfiveYearsMember_daf25fff-002e-461f-b891-bd1ea9416920" xlink:href="trs-20241231.xsd#trs_UsefulLifeFifteenToTwentyfiveYearsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_82929b10-b69b-4115-9b14-1799fbd576fe" xlink:to="loc_trs_UsefulLifeFifteenToTwentyfiveYearsMember_daf25fff-002e-461f-b891-bd1ea9416920" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_UsefulLifeOneToFifteenYearsMember_809ea8da-0a3b-4901-85f8-0982de8163ed" xlink:href="trs-20241231.xsd#trs_UsefulLifeOneToFifteenYearsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_82929b10-b69b-4115-9b14-1799fbd576fe" xlink:to="loc_trs_UsefulLifeOneToFifteenYearsMember_809ea8da-0a3b-4901-85f8-0982de8163ed" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_UsefulLifeSeventeenToThirtyYearsMember_0f906ccc-c02b-4694-8a7c-e83aeb3676a7" xlink:href="trs-20241231.xsd#trs_UsefulLifeSeventeenToThirtyYearsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_82929b10-b69b-4115-9b14-1799fbd576fe" xlink:to="loc_trs_UsefulLifeSeventeenToThirtyYearsMember_0f906ccc-c02b-4694-8a7c-e83aeb3676a7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_bc9f6eaa-14b9-4848-9472-a324753ee681" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassTable_c38f519b-d1df-4de9-ba0e-deb77216228a" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_bc9f6eaa-14b9-4848-9472-a324753ee681" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_bc9f6eaa-14b9-4848-9472-a324753ee681_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_bc9f6eaa-14b9-4848-9472-a324753ee681" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_bc9f6eaa-14b9-4848-9472-a324753ee681_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_4189d6f1-02c2-4d9d-845d-29b9c6c46bdd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_bc9f6eaa-14b9-4848-9472-a324753ee681" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_4189d6f1-02c2-4d9d-845d-29b9c6c46bdd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_85ba0a2d-2dbe-40d9-b519-94c677466663" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TrademarksAndTradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_4189d6f1-02c2-4d9d-845d-29b9c6c46bdd" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_85ba0a2d-2dbe-40d9-b519-94c677466663" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_d38e7319-449e-4b51-9f76-deff3df828ad" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassTable_c38f519b-d1df-4de9-ba0e-deb77216228a" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_d38e7319-449e-4b51-9f76-deff3df828ad" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_d38e7319-449e-4b51-9f76-deff3df828ad_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_d38e7319-449e-4b51-9f76-deff3df828ad" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_d38e7319-449e-4b51-9f76-deff3df828ad_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f55bd172-7d68-4601-bd71-7cbad36aa60f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_d38e7319-449e-4b51-9f76-deff3df828ad" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f55bd172-7d68-4601-bd71-7cbad36aa60f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_5c23e759-7f73-48ce-9c4a-fcc23f9289aa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f55bd172-7d68-4601-bd71-7cbad36aa60f" xlink:to="loc_us-gaap_CustomerRelationshipsMember_5c23e759-7f73-48ce-9c4a-fcc23f9289aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_TechnologyAndOtherMember_3f36fb8a-45df-4c39-9097-d4c50eee67db" xlink:href="trs-20241231.xsd#trs_TechnologyAndOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f55bd172-7d68-4601-bd71-7cbad36aa60f" xlink:to="loc_trs_TechnologyAndOtherMember_3f36fb8a-45df-4c39-9097-d4c50eee67db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_831cb72c-4e63-40c8-ac7a-c0e957a3bb0d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_IntangibleAssetsExcludingGoodwillLineItems_cf185ec7-0c54-4e32-bcab-ccf31ba82cf9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_831cb72c-4e63-40c8-ac7a-c0e957a3bb0d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_29a5b7a1-2807-4a6a-b949-d092c3c437f1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_IntangibleAssetsExcludingGoodwillLineItems_cf185ec7-0c54-4e32-bcab-ccf31ba82cf9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_29a5b7a1-2807-4a6a-b949-d092c3c437f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_0ff333a4-5248-46da-be7f-03e62c446f15" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_IntangibleAssetsExcludingGoodwillLineItems_cf185ec7-0c54-4e32-bcab-ccf31ba82cf9" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_0ff333a4-5248-46da-be7f-03e62c446f15" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_8ee541e9-287c-46bd-9730-43844903a299" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_IntangibleAssetsExcludingGoodwillLineItems_cf185ec7-0c54-4e32-bcab-ccf31ba82cf9" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_8ee541e9-287c-46bd-9730-43844903a299" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_TotalOtherIntangibleAssetsGross_814076dd-c13c-4002-a919-42efb9631d94" xlink:href="trs-20241231.xsd#trs_TotalOtherIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_IntangibleAssetsExcludingGoodwillLineItems_cf185ec7-0c54-4e32-bcab-ccf31ba82cf9" xlink:to="loc_trs_TotalOtherIntangibleAssetsGross_814076dd-c13c-4002-a919-42efb9631d94" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/GoodwillandOtherIntangibleAssetsOtherIntangibleAssetsAmortizationExpenseDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#GoodwillandOtherIntangibleAssetsOtherIntangibleAssetsAmortizationExpenseDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/GoodwillandOtherIntangibleAssetsOtherIntangibleAssetsAmortizationExpenseDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_trs_AmortizationOfIntangibleAssetsLineItems_b79f0ac5-f49c-41dc-b4c0-7abac5086d24" xlink:href="trs-20241231.xsd#trs_AmortizationOfIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ScheduleOfAmortizationOfIntangibleAssetsTable_6d3f7ff6-7bd6-4e9c-adab-b9ae03777857" xlink:href="trs-20241231.xsd#trs_ScheduleOfAmortizationOfIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_trs_AmortizationOfIntangibleAssetsLineItems_b79f0ac5-f49c-41dc-b4c0-7abac5086d24" xlink:to="loc_trs_ScheduleOfAmortizationOfIntangibleAssetsTable_6d3f7ff6-7bd6-4e9c-adab-b9ae03777857" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_66834e8d-7731-423a-9a33-6ac645cf5bce" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfAmortizationOfIntangibleAssetsTable_6d3f7ff6-7bd6-4e9c-adab-b9ae03777857" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_66834e8d-7731-423a-9a33-6ac645cf5bce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_66834e8d-7731-423a-9a33-6ac645cf5bce_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_66834e8d-7731-423a-9a33-6ac645cf5bce" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_66834e8d-7731-423a-9a33-6ac645cf5bce_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_d311271f-c7ce-47ac-b6e3-7ccf766a2be6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_66834e8d-7731-423a-9a33-6ac645cf5bce" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_d311271f-c7ce-47ac-b6e3-7ccf766a2be6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_c81a5533-b1e5-4de8-bff7-18481e6be2f3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_d311271f-c7ce-47ac-b6e3-7ccf766a2be6" xlink:to="loc_us-gaap_CostOfSalesMember_c81a5533-b1e5-4de8-bff7-18481e6be2f3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_8f75e957-1d7b-45e3-b6d3-b1fdcf40e282" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_d311271f-c7ce-47ac-b6e3-7ccf766a2be6" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_8f75e957-1d7b-45e3-b6d3-b1fdcf40e282" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_fad551d2-7e7c-48aa-a2d6-90351633ce25" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfAmortizationOfIntangibleAssetsTable_6d3f7ff6-7bd6-4e9c-adab-b9ae03777857" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_fad551d2-7e7c-48aa-a2d6-90351633ce25" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_fad551d2-7e7c-48aa-a2d6-90351633ce25_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_fad551d2-7e7c-48aa-a2d6-90351633ce25" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_fad551d2-7e7c-48aa-a2d6-90351633ce25_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_00e12c5a-a54c-4fcb-a093-55c854c07bd4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_fad551d2-7e7c-48aa-a2d6-90351633ce25" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_00e12c5a-a54c-4fcb-a093-55c854c07bd4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_TechnologyAndOtherMember_4e791757-8ae9-4879-9a30-62efc768464f" xlink:href="trs-20241231.xsd#trs_TechnologyAndOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_00e12c5a-a54c-4fcb-a093-55c854c07bd4" xlink:to="loc_trs_TechnologyAndOtherMember_4e791757-8ae9-4879-9a30-62efc768464f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_73ed6b6f-004b-4beb-8a93-272074cd2447" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_00e12c5a-a54c-4fcb-a093-55c854c07bd4" xlink:to="loc_us-gaap_CustomerRelationshipsMember_73ed6b6f-004b-4beb-8a93-272074cd2447" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_5206705f-12d3-4839-8d47-b785c7b44b0c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_AmortizationOfIntangibleAssetsLineItems_b79f0ac5-f49c-41dc-b4c0-7abac5086d24" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_5206705f-12d3-4839-8d47-b785c7b44b0c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/PropertyandEquipmentNetPropertyandEquipmentTableDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#PropertyandEquipmentNetPropertyandEquipmentTableDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/PropertyandEquipmentNetPropertyandEquipmentTableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_c6913463-bc3d-4dd8-828d-42d8e7e8e040" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ce630298-9b57-484f-8f42-a0e15a7f070f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_c6913463-bc3d-4dd8-828d-42d8e7e8e040" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ce630298-9b57-484f-8f42-a0e15a7f070f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_ac77dffa-3c50-4380-8742-a010773ad405" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_ce630298-9b57-484f-8f42-a0e15a7f070f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_ac77dffa-3c50-4380-8742-a010773ad405" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_ac77dffa-3c50-4380-8742-a010773ad405_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_ac77dffa-3c50-4380-8742-a010773ad405" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_ac77dffa-3c50-4380-8742-a010773ad405_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_0809e06f-ac01-427a-87c9-2f4f11a47664" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_ac77dffa-3c50-4380-8742-a010773ad405" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_0809e06f-ac01-427a-87c9-2f4f11a47664" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandAndLandImprovementsMember_3e16e4b6-a46d-41ee-a19d-01066bd98288" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LandAndLandImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_0809e06f-ac01-427a-87c9-2f4f11a47664" xlink:to="loc_us-gaap_LandAndLandImprovementsMember_3e16e4b6-a46d-41ee-a19d-01066bd98288" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingMember_8014cfe2-a85e-4a9c-aea5-2b05c27d7d56" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BuildingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_0809e06f-ac01-427a-87c9-2f4f11a47664" xlink:to="loc_us-gaap_BuildingMember_8014cfe2-a85e-4a9c-aea5-2b05c27d7d56" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_13156525-dc65-4247-aad0-358f155e8a9c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_0809e06f-ac01-427a-87c9-2f4f11a47664" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_13156525-dc65-4247-aad0-358f155e8a9c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_fd27c277-578f-4103-97b6-ab388bb6ce06" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_c6913463-bc3d-4dd8-828d-42d8e7e8e040" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_fd27c277-578f-4103-97b6-ab388bb6ce06" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_2ac5cd24-2733-4d44-863b-43534518a82a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_c6913463-bc3d-4dd8-828d-42d8e7e8e040" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_2ac5cd24-2733-4d44-863b-43534518a82a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_c9ae6fb3-006e-4fb5-b284-b4600d7a0ea0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_c6913463-bc3d-4dd8-828d-42d8e7e8e040" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_c9ae6fb3-006e-4fb5-b284-b4600d7a0ea0" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/PropertyandEquipmentNetDepreciationExpenseTableDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#PropertyandEquipmentNetDepreciationExpenseTableDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/PropertyandEquipmentNetDepreciationExpenseTableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_trs_DepreciationExpenseLineItems_84acf435-091b-43b5-a017-ff1fd9f4cb2d" xlink:href="trs-20241231.xsd#trs_DepreciationExpenseLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ScheduleOfDepreciationExpenseTable_5fa80f4d-db85-4bdc-85cb-25b5b3a5b4bb" xlink:href="trs-20241231.xsd#trs_ScheduleOfDepreciationExpenseTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_trs_DepreciationExpenseLineItems_84acf435-091b-43b5-a017-ff1fd9f4cb2d" xlink:to="loc_trs_ScheduleOfDepreciationExpenseTable_5fa80f4d-db85-4bdc-85cb-25b5b3a5b4bb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_d57efeae-731e-4d97-8a77-34748819b77b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfDepreciationExpenseTable_5fa80f4d-db85-4bdc-85cb-25b5b3a5b4bb" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_d57efeae-731e-4d97-8a77-34748819b77b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_d57efeae-731e-4d97-8a77-34748819b77b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_d57efeae-731e-4d97-8a77-34748819b77b" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_d57efeae-731e-4d97-8a77-34748819b77b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_6c69f501-7832-4b92-8d5a-d0d9ddb016c6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_d57efeae-731e-4d97-8a77-34748819b77b" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_6c69f501-7832-4b92-8d5a-d0d9ddb016c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_dc0982d3-1d41-4b24-996c-0a3286156c86" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_6c69f501-7832-4b92-8d5a-d0d9ddb016c6" xlink:to="loc_us-gaap_CostOfSalesMember_dc0982d3-1d41-4b24-996c-0a3286156c86" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_b22f59cf-519b-4989-8fa3-6314d84886fb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_6c69f501-7832-4b92-8d5a-d0d9ddb016c6" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_b22f59cf-519b-4989-8fa3-6314d84886fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_0349b73e-c9ea-4758-925f-4912a3f38266" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementOperatingActivitiesSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfDepreciationExpenseTable_5fa80f4d-db85-4bdc-85cb-25b5b3a5b4bb" xlink:to="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_0349b73e-c9ea-4758-925f-4912a3f38266" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_0349b73e-c9ea-4758-925f-4912a3f38266_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentOperatingActivitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_0349b73e-c9ea-4758-925f-4912a3f38266" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_0349b73e-c9ea-4758-925f-4912a3f38266_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_c837f312-af77-44e3-abd8-22ed8723a821" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentOperatingActivitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_0349b73e-c9ea-4758-925f-4912a3f38266" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_c837f312-af77-44e3-abd8-22ed8723a821" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentContinuingOperationsMember_345c75c8-d95b-40ad-b274-bbee70e48bc4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentContinuingOperationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentOperatingActivitiesDomain_c837f312-af77-44e3-abd8-22ed8723a821" xlink:to="loc_us-gaap_SegmentContinuingOperationsMember_345c75c8-d95b-40ad-b274-bbee70e48bc4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Depreciation_262c24a3-dcf2-485c-bec0-f7d943ace4c2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Depreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DepreciationExpenseLineItems_84acf435-091b-43b5-a017-ff1fd9f4cb2d" xlink:to="loc_us-gaap_Depreciation_262c24a3-dcf2-485c-bec0-f7d943ace4c2" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/PropertyandEquipmentNetDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#PropertyandEquipmentNetDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/PropertyandEquipmentNetDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_trs_ScheduleOfDepreciationExpenseLineItems_c3b492e0-df22-4349-afaf-b2dbecf4d4d9" xlink:href="trs-20241231.xsd#trs_ScheduleOfDepreciationExpenseLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ScheduleOfDepreciationExpenseTable_51c0813c-cfa0-44d8-8ef3-addc42255bfb" xlink:href="trs-20241231.xsd#trs_ScheduleOfDepreciationExpenseTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_trs_ScheduleOfDepreciationExpenseLineItems_c3b492e0-df22-4349-afaf-b2dbecf4d4d9" xlink:to="loc_trs_ScheduleOfDepreciationExpenseTable_51c0813c-cfa0-44d8-8ef3-addc42255bfb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_c9bc4a97-8adc-47d6-8ea7-5b9f1fc0ba96" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfDepreciationExpenseTable_51c0813c-cfa0-44d8-8ef3-addc42255bfb" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_c9bc4a97-8adc-47d6-8ea7-5b9f1fc0ba96" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_c9bc4a97-8adc-47d6-8ea7-5b9f1fc0ba96_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_c9bc4a97-8adc-47d6-8ea7-5b9f1fc0ba96" xlink:to="loc_us-gaap_SegmentDomain_c9bc4a97-8adc-47d6-8ea7-5b9f1fc0ba96_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_8a0e54e1-ca0d-438d-a7b2-0da487ad6be9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_c9bc4a97-8adc-47d6-8ea7-5b9f1fc0ba96" xlink:to="loc_us-gaap_SegmentDomain_8a0e54e1-ca0d-438d-a7b2-0da487ad6be9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_SpecialtyProductsReportableSegmentMember_dacb78ea-b081-4e9a-aa20-007db83804a3" xlink:href="trs-20241231.xsd#trs_SpecialtyProductsReportableSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_8a0e54e1-ca0d-438d-a7b2-0da487ad6be9" xlink:to="loc_trs_SpecialtyProductsReportableSegmentMember_dacb78ea-b081-4e9a-aa20-007db83804a3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveAcceleratedDepreciation_60ba7022-827e-4eef-bcce-fb6e0cf70cbe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringReserveAcceleratedDepreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_ScheduleOfDepreciationExpenseLineItems_c3b492e0-df22-4349-afaf-b2dbecf4d4d9" xlink:to="loc_us-gaap_RestructuringReserveAcceleratedDepreciation_60ba7022-827e-4eef-bcce-fb6e0cf70cbe" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/LongtermDebtDebtTableDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#LongtermDebtDebtTableDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/LongtermDebtDebtTableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_eb83a69e-f4a9-4f48-92ba-0cb2cd07bab0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ScheduleOfDebtInstrumentsTable_d56f900f-37d4-474d-94aa-b423aec283b4" xlink:href="trs-20241231.xsd#trs_ScheduleOfDebtInstrumentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_eb83a69e-f4a9-4f48-92ba-0cb2cd07bab0" xlink:to="loc_trs_ScheduleOfDebtInstrumentsTable_d56f900f-37d4-474d-94aa-b423aec283b4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_4d64af8e-cd80-4277-b411-a1bb1df07f24" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfDebtInstrumentsTable_d56f900f-37d4-474d-94aa-b423aec283b4" xlink:to="loc_us-gaap_DebtInstrumentAxis_4d64af8e-cd80-4277-b411-a1bb1df07f24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_4d64af8e-cd80-4277-b411-a1bb1df07f24_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_4d64af8e-cd80-4277-b411-a1bb1df07f24" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_4d64af8e-cd80-4277-b411-a1bb1df07f24_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_cece20c1-e93d-4783-bb76-ec36edbddebe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_4d64af8e-cd80-4277-b411-a1bb1df07f24" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_cece20c1-e93d-4783-bb76-ec36edbddebe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_A4125SeniorUnsecuredNotesDue2029Member_9325d244-e7f9-4705-8420-64a7056277dc" xlink:href="trs-20241231.xsd#trs_A4125SeniorUnsecuredNotesDue2029Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cece20c1-e93d-4783-bb76-ec36edbddebe" xlink:to="loc_trs_A4125SeniorUnsecuredNotesDue2029Member_9325d244-e7f9-4705-8420-64a7056277dc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_A4.875SeniorUnsecuredNotesDue2025Member_8ed7ec99-6b30-40a7-9651-aa43ed816e06" xlink:href="trs-20241231.xsd#trs_A4.875SeniorUnsecuredNotesDue2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cece20c1-e93d-4783-bb76-ec36edbddebe" xlink:to="loc_trs_A4.875SeniorUnsecuredNotesDue2025Member_8ed7ec99-6b30-40a7-9651-aa43ed816e06" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_CreditAgreementMember_eb2bc9df-1fc4-4840-8594-833dc7054c03" xlink:href="trs-20241231.xsd#trs_CreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cece20c1-e93d-4783-bb76-ec36edbddebe" xlink:to="loc_trs_CreditAgreementMember_eb2bc9df-1fc4-4840-8594-833dc7054c03" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ReceivablesFacilityandotherMemberMember_84b86ef6-02ab-4888-920f-20620dec34cb" xlink:href="trs-20241231.xsd#trs_ReceivablesFacilityandotherMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_cece20c1-e93d-4783-bb76-ec36edbddebe" xlink:to="loc_trs_ReceivablesFacilityandotherMemberMember_84b86ef6-02ab-4888-920f-20620dec34cb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndCapitalLeaseObligations_6d9860bc-12dc-47de-8e1d-ab013597f2ca" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtAndCapitalLeaseObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_eb83a69e-f4a9-4f48-92ba-0cb2cd07bab0" xlink:to="loc_us-gaap_DebtAndCapitalLeaseObligations_6d9860bc-12dc-47de-8e1d-ab013597f2ca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_0d0f80b9-fc3e-4771-bae7-bb470c720e0d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_eb83a69e-f4a9-4f48-92ba-0cb2cd07bab0" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_0d0f80b9-fc3e-4771-bae7-bb470c720e0d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtCurrent_5f477645-57a4-4426-b961-cecb3bdc40fe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_eb83a69e-f4a9-4f48-92ba-0cb2cd07bab0" xlink:to="loc_us-gaap_DebtCurrent_5f477645-57a4-4426-b961-cecb3bdc40fe" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_20b9f405-955c-4891-8c5b-1fbf5b002efa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_eb83a69e-f4a9-4f48-92ba-0cb2cd07bab0" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_20b9f405-955c-4891-8c5b-1fbf5b002efa" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/LongtermDebtSeniorNotesDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#LongtermDebtSeniorNotesDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/LongtermDebtSeniorNotesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_28673651-9345-4e4d-8746-efae1c9661ed" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_us-gaap_DebtInstrumentTable_28673651-9345-4e4d-8746-efae1c9661ed" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_8c639bad-94a2-47d0-b662-5c47faeed0a1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_28673651-9345-4e4d-8746-efae1c9661ed" xlink:to="loc_us-gaap_CreditFacilityAxis_8c639bad-94a2-47d0-b662-5c47faeed0a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_8c639bad-94a2-47d0-b662-5c47faeed0a1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_8c639bad-94a2-47d0-b662-5c47faeed0a1" xlink:to="loc_us-gaap_CreditFacilityDomain_8c639bad-94a2-47d0-b662-5c47faeed0a1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_eb974266-8539-4398-b0ef-d9270d9c46d1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_8c639bad-94a2-47d0-b662-5c47faeed0a1" xlink:to="loc_us-gaap_CreditFacilityDomain_eb974266-8539-4398-b0ef-d9270d9c46d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_2cdd93c3-4496-432c-b64b-b96fda36ddbe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_28673651-9345-4e4d-8746-efae1c9661ed" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_2cdd93c3-4496-432c-b64b-b96fda36ddbe" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_2cdd93c3-4496-432c-b64b-b96fda36ddbe_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_2cdd93c3-4496-432c-b64b-b96fda36ddbe" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_2cdd93c3-4496-432c-b64b-b96fda36ddbe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_9f5acfaa-52cc-4aec-b0f8-3c3a37626434" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_2cdd93c3-4496-432c-b64b-b96fda36ddbe" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_9f5acfaa-52cc-4aec-b0f8-3c3a37626434" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_41692c2c-a0c3-48bf-b2ef-fce8994a966a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_9f5acfaa-52cc-4aec-b0f8-3c3a37626434" xlink:to="loc_us-gaap_SeniorNotesMember_41692c2c-a0c3-48bf-b2ef-fce8994a966a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_SeniorSecuredTermLoanMember_082fdfa2-d942-4704-9370-26991d11a39f" xlink:href="trs-20241231.xsd#trs_SeniorSecuredTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_9f5acfaa-52cc-4aec-b0f8-3c3a37626434" xlink:to="loc_trs_SeniorSecuredTermLoanMember_082fdfa2-d942-4704-9370-26991d11a39f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_e715770f-b0e6-411a-af42-0de5b9ef0dd7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_9f5acfaa-52cc-4aec-b0f8-3c3a37626434" xlink:to="loc_us-gaap_SecuredDebtMember_e715770f-b0e6-411a-af42-0de5b9ef0dd7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_c6bd2bc9-3bed-461c-82f5-74b6e847d99d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_9f5acfaa-52cc-4aec-b0f8-3c3a37626434" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_c6bd2bc9-3bed-461c-82f5-74b6e847d99d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_3cf4514a-7ff8-4ea2-a76d-1143af29dc06" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_28673651-9345-4e4d-8746-efae1c9661ed" xlink:to="loc_us-gaap_DebtInstrumentAxis_3cf4514a-7ff8-4ea2-a76d-1143af29dc06" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_3cf4514a-7ff8-4ea2-a76d-1143af29dc06_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_3cf4514a-7ff8-4ea2-a76d-1143af29dc06" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_3cf4514a-7ff8-4ea2-a76d-1143af29dc06_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_3659d8f6-a866-4fb0-bed6-1e09980caa41" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_3cf4514a-7ff8-4ea2-a76d-1143af29dc06" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_3659d8f6-a866-4fb0-bed6-1e09980caa41" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_A4.875SeniorUnsecuredNotesDue2025Member_7a459677-bda8-4e97-80b3-75ff1c9282ab" xlink:href="trs-20241231.xsd#trs_A4.875SeniorUnsecuredNotesDue2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_3659d8f6-a866-4fb0-bed6-1e09980caa41" xlink:to="loc_trs_A4.875SeniorUnsecuredNotesDue2025Member_7a459677-bda8-4e97-80b3-75ff1c9282ab" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_A4125SeniorUnsecuredNotesDue2029Member_c1a4a0f2-36b2-422e-94f3-9e8b6ff4d230" xlink:href="trs-20241231.xsd#trs_A4125SeniorUnsecuredNotesDue2029Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_3659d8f6-a866-4fb0-bed6-1e09980caa41" xlink:to="loc_trs_A4125SeniorUnsecuredNotesDue2029Member_c1a4a0f2-36b2-422e-94f3-9e8b6ff4d230" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_aa8939a9-a1f1-4fea-8ea1-9688252b8a50" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_28673651-9345-4e4d-8746-efae1c9661ed" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_aa8939a9-a1f1-4fea-8ea1-9688252b8a50" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_aa8939a9-a1f1-4fea-8ea1-9688252b8a50_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_aa8939a9-a1f1-4fea-8ea1-9688252b8a50" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_aa8939a9-a1f1-4fea-8ea1-9688252b8a50_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_2e19d9d7-5829-45d0-926c-5d96ecdd36a0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodAxis_aa8939a9-a1f1-4fea-8ea1-9688252b8a50" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_2e19d9d7-5829-45d0-926c-5d96ecdd36a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodOneMember_d22775e3-efde-44f0-9aab-3a2780c5a8c0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_2e19d9d7-5829-45d0-926c-5d96ecdd36a0" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodOneMember_d22775e3-efde-44f0-9aab-3a2780c5a8c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodTwoMember_eeebdcb1-5249-4136-b485-62e8867b4b8f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_2e19d9d7-5829-45d0-926c-5d96ecdd36a0" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodTwoMember_eeebdcb1-5249-4136-b485-62e8867b4b8f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodThreeMember_0f46c3d9-55f1-4c8b-b2a2-738aad5a504c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_2e19d9d7-5829-45d0-926c-5d96ecdd36a0" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodThreeMember_0f46c3d9-55f1-4c8b-b2a2-738aad5a504c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPeriodFourMember_21fe6538-4ac2-4f37-bd28-4f6c786fc1f0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPeriodFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentRedemptionPeriodDomain_2e19d9d7-5829-45d0-926c-5d96ecdd36a0" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPeriodFourMember_21fe6538-4ac2-4f37-bd28-4f6c786fc1f0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_4a1e3e3c-1206-49a1-ad1d-292d75fbdcca" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_4a1e3e3c-1206-49a1-ad1d-292d75fbdcca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_7bd72804-c91a-40a2-9e05-96ae9d71cbdd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_7bd72804-c91a-40a2-9e05-96ae9d71cbdd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentMaturityDate_f7df5c68-1821-4acb-8bc2-16f1dfdc3aac" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentMaturityDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_us-gaap_DebtInstrumentMaturityDate_f7df5c68-1821-4acb-8bc2-16f1dfdc3aac" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RepaymentsOfDebt_435978aa-1433-4af7-82ac-86f352191bbe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RepaymentsOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_us-gaap_RepaymentsOfDebt_435978aa-1433-4af7-82ac-86f352191bbe" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestPaid_8c68c877-611e-446a-a388-8827b67d8b41" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_us-gaap_InterestPaid_8c68c877-611e-446a-a388-8827b67d8b41" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfFinancingCosts_fe178a97-86ea-44d3-83ce-970bbdff1084" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsOfFinancingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_us-gaap_PaymentsOfFinancingCosts_fe178a97-86ea-44d3-83ce-970bbdff1084" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNoncurrentNet_203f4afc-1ea4-4341-b2c1-6bfacedc7b3f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredFinanceCostsNoncurrentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_us-gaap_DeferredFinanceCostsNoncurrentNet_203f4afc-1ea4-4341-b2c1-6bfacedc7b3f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts_42ad2285-ffd1-4cac-8c0c-eadfb6a0ea1b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts_42ad2285-ffd1-4cac-8c0c-eadfb6a0ea1b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentDateOfFirstRequiredPayment1_d0c4e2c1-acf2-4d9f-9784-ff2283ba645d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentDateOfFirstRequiredPayment1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_us-gaap_DebtInstrumentDateOfFirstRequiredPayment1_d0c4e2c1-acf2-4d9f-9784-ff2283ba645d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Percentageofprincipalthatcanberedeemedwithcashproceedsfromanequityoffering_879f299f-9ee9-40e5-b6e2-a741dea50583" xlink:href="trs-20241231.xsd#trs_Percentageofprincipalthatcanberedeemedwithcashproceedsfromanequityoffering"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_trs_Percentageofprincipalthatcanberedeemedwithcashproceedsfromanequityoffering_879f299f-9ee9-40e5-b6e2-a741dea50583" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Debtinstrumentredemptionpricewithnetproceedsfromequityoffering_99732dbf-aa3f-425e-b4e8-2395e7113a0b" xlink:href="trs-20241231.xsd#trs_Debtinstrumentredemptionpricewithnetproceedsfromequityoffering"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_trs_Debtinstrumentredemptionpricewithnetproceedsfromequityoffering_99732dbf-aa3f-425e-b4e8-2395e7113a0b" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_650fec5f-fe14-42b6-95de-34939f539cea" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_650fec5f-fe14-42b6-95de-34939f539cea" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDebtExtinguishmentCosts_afe11d0b-f57e-4f99-b11e-9108439ae232" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsOfDebtExtinguishmentCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_us-gaap_PaymentsOfDebtExtinguishmentCosts_afe11d0b-f57e-4f99-b11e-9108439ae232" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_0b48a031-e833-410b-986b-93324743cb80" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WriteOffOfDeferredDebtIssuanceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_fb09f237-c6ea-42ff-80bc-36136b2b0cc7" xlink:to="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_0b48a031-e833-410b-986b-93324743cb80" xlink:type="arc" order="13"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/LongtermDebtCreditAgreementDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#LongtermDebtCreditAgreementDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/LongtermDebtCreditAgreementDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_3f5f5b0e-7d68-4f07-8a5a-711cfb539aab" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_us-gaap_DebtInstrumentTable_3f5f5b0e-7d68-4f07-8a5a-711cfb539aab" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_944485fc-f1ab-4a6f-911b-e0942f0198d3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3f5f5b0e-7d68-4f07-8a5a-711cfb539aab" xlink:to="loc_us-gaap_CreditFacilityAxis_944485fc-f1ab-4a6f-911b-e0942f0198d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_944485fc-f1ab-4a6f-911b-e0942f0198d3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_944485fc-f1ab-4a6f-911b-e0942f0198d3" xlink:to="loc_us-gaap_CreditFacilityDomain_944485fc-f1ab-4a6f-911b-e0942f0198d3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_a5e82773-7b7d-487a-b244-2a733d7462ec" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_944485fc-f1ab-4a6f-911b-e0942f0198d3" xlink:to="loc_us-gaap_CreditFacilityDomain_a5e82773-7b7d-487a-b244-2a733d7462ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_1887ca9f-f434-493e-876e-6fdfd47c5cb7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_a5e82773-7b7d-487a-b244-2a733d7462ec" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_1887ca9f-f434-493e-876e-6fdfd47c5cb7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LetterOfCreditMember_eb98483e-98f8-4f31-8a37-543d9eb3684d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LetterOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_a5e82773-7b7d-487a-b244-2a733d7462ec" xlink:to="loc_us-gaap_LetterOfCreditMember_eb98483e-98f8-4f31-8a37-543d9eb3684d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_1429577b-42a3-43b2-9597-ae6bda4a5191" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3f5f5b0e-7d68-4f07-8a5a-711cfb539aab" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_1429577b-42a3-43b2-9597-ae6bda4a5191" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_1429577b-42a3-43b2-9597-ae6bda4a5191_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_1429577b-42a3-43b2-9597-ae6bda4a5191" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_1429577b-42a3-43b2-9597-ae6bda4a5191_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_68597c7b-439e-449c-981c-d22f88f57c00" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_1429577b-42a3-43b2-9597-ae6bda4a5191" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_68597c7b-439e-449c-981c-d22f88f57c00" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_SeniorSecuredTermLoanMember_7f388244-a777-4fa7-b16c-be48478ba310" xlink:href="trs-20241231.xsd#trs_SeniorSecuredTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_68597c7b-439e-449c-981c-d22f88f57c00" xlink:to="loc_trs_SeniorSecuredTermLoanMember_7f388244-a777-4fa7-b16c-be48478ba310" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_64203123-1e42-4d67-a5e6-c754b0da93a6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_68597c7b-439e-449c-981c-d22f88f57c00" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_64203123-1e42-4d67-a5e6-c754b0da93a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_RevolvingCreditAndTermLoanFacilitiesMember_056e1f80-c561-4861-973e-ec075f46011c" xlink:href="trs-20241231.xsd#trs_RevolvingCreditAndTermLoanFacilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_68597c7b-439e-449c-981c-d22f88f57c00" xlink:to="loc_trs_RevolvingCreditAndTermLoanFacilitiesMember_056e1f80-c561-4861-973e-ec075f46011c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_39356044-9462-4110-84e1-8292b81c57f1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3f5f5b0e-7d68-4f07-8a5a-711cfb539aab" xlink:to="loc_us-gaap_DebtInstrumentAxis_39356044-9462-4110-84e1-8292b81c57f1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_39356044-9462-4110-84e1-8292b81c57f1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_39356044-9462-4110-84e1-8292b81c57f1" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_39356044-9462-4110-84e1-8292b81c57f1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_043a5df4-87a1-434f-a47d-7ba1cdceda67" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_39356044-9462-4110-84e1-8292b81c57f1" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_043a5df4-87a1-434f-a47d-7ba1cdceda67" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_cdb13d7e-733b-40ae-bcc6-5d73b28ded1d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_043a5df4-87a1-434f-a47d-7ba1cdceda67" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_cdb13d7e-733b-40ae-bcc6-5d73b28ded1d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_SeniorSecuredTermLoanMember_936205d9-bce5-46b1-846d-a3f52d1bcc0b" xlink:href="trs-20241231.xsd#trs_SeniorSecuredTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_043a5df4-87a1-434f-a47d-7ba1cdceda67" xlink:to="loc_trs_SeniorSecuredTermLoanMember_936205d9-bce5-46b1-846d-a3f52d1bcc0b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_BankdebtandreceivablesfacilityMember_b546ca2f-9461-49c2-8560-7e1412929cea" xlink:href="trs-20241231.xsd#trs_BankdebtandreceivablesfacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_043a5df4-87a1-434f-a47d-7ba1cdceda67" xlink:to="loc_trs_BankdebtandreceivablesfacilityMember_b546ca2f-9461-49c2-8560-7e1412929cea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicDistributionAxis_1dec49e8-cb26-4cc2-9a8b-1c8d1c98d2ba" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeographicDistributionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_3f5f5b0e-7d68-4f07-8a5a-711cfb539aab" xlink:to="loc_us-gaap_GeographicDistributionAxis_1dec49e8-cb26-4cc2-9a8b-1c8d1c98d2ba" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicDistributionDomain_1dec49e8-cb26-4cc2-9a8b-1c8d1c98d2ba_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeographicDistributionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GeographicDistributionAxis_1dec49e8-cb26-4cc2-9a8b-1c8d1c98d2ba" xlink:to="loc_us-gaap_GeographicDistributionDomain_1dec49e8-cb26-4cc2-9a8b-1c8d1c98d2ba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicDistributionDomain_71edf84e-73a2-4f8c-9da2-0beac2716d3d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeographicDistributionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GeographicDistributionAxis_1dec49e8-cb26-4cc2-9a8b-1c8d1c98d2ba" xlink:to="loc_us-gaap_GeographicDistributionDomain_71edf84e-73a2-4f8c-9da2-0beac2716d3d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicDistributionForeignMember_7b30ce81-a09d-4cdb-805e-c6783710dd70" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeographicDistributionForeignMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GeographicDistributionDomain_71edf84e-73a2-4f8c-9da2-0beac2716d3d" xlink:to="loc_us-gaap_GeographicDistributionForeignMember_7b30ce81-a09d-4cdb-805e-c6783710dd70" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicDistributionDomesticMember_782a709c-72ae-40e0-8d71-735cc67bec49" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GeographicDistributionDomesticMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GeographicDistributionDomain_71edf84e-73a2-4f8c-9da2-0beac2716d3d" xlink:to="loc_us-gaap_GeographicDistributionDomesticMember_782a709c-72ae-40e0-8d71-735cc67bec49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_8f68e7ab-c6f4-4fbb-801e-7efa38974e11" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_8f68e7ab-c6f4-4fbb-801e-7efa38974e11" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases_f7977620-96ea-49e8-9832-c2a47def9b75" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases_f7977620-96ea-49e8-9832-c2a47def9b75" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentMaturityDate_9b5599c3-ad79-4f0c-9f02-99ac6d8bb5d7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentMaturityDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_us-gaap_DebtInstrumentMaturityDate_9b5599c3-ad79-4f0c-9f02-99ac6d8bb5d7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_26140794-9e46-438d-99d0-7df97070ad7b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_26140794-9e46-438d-99d0-7df97070ad7b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_IncrementalDebtCommitmentsCapacity_b37a4cde-db18-4b84-9fd7-4427be84e40a" xlink:href="trs-20241231.xsd#trs_IncrementalDebtCommitmentsCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_trs_IncrementalDebtCommitmentsCapacity_b37a4cde-db18-4b84-9fd7-4427be84e40a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_NetLeverageRatio_aadf0421-3321-462f-b2bb-d14075c14691" xlink:href="trs-20241231.xsd#trs_NetLeverageRatio"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_trs_NetLeverageRatio_aadf0421-3321-462f-b2bb-d14075c14691" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_6b438426-0341-4f11-b3ab-a8133fbe1a34" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_6b438426-0341-4f11-b3ab-a8133fbe1a34" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_328d89ee-33c5-4127-a733-e0b9b5188ebd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_328d89ee-33c5-4127-a733-e0b9b5188ebd" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_071d0d4e-116c-4c54-a23c-89833147d0cd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_us-gaap_LineOfCredit_071d0d4e-116c-4c54-a23c-89833147d0cd" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_09b113f1-677f-4f4a-b8d5-fc75ceb08a81" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_09b113f1-677f-4f4a-b8d5-fc75ceb08a81" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_94d0d3ef-a940-41c4-b598-c50130890224" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_94d0d3ef-a940-41c4-b598-c50130890224" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfFinancingCosts_d1bd82ee-8df5-415e-ac2a-d68629136bb2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsOfFinancingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_us-gaap_PaymentsOfFinancingCosts_d1bd82ee-8df5-415e-ac2a-d68629136bb2" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNoncurrentNet_e0a0a80a-493e-4054-9536-fae1aca45065" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredFinanceCostsNoncurrentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_us-gaap_DeferredFinanceCostsNoncurrentNet_e0a0a80a-493e-4054-9536-fae1aca45065" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_53b01153-4226-4847-b3a8-8d2725a4f7ff" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_53b01153-4226-4847-b3a8-8d2725a4f7ff" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_b8c8abeb-6042-48f6-89de-4051f91a20c1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WriteOffOfDeferredDebtIssuanceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_b8c8abeb-6042-48f6-89de-4051f91a20c1" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_LineOfCreditBorrowingCapacityConsideringCovenantRestrictions_7d8e48bb-65d5-4afe-9bb8-2ddd7e15804d" xlink:href="trs-20241231.xsd#trs_LineOfCreditBorrowingCapacityConsideringCovenantRestrictions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_df062092-18f6-4ad7-928d-54824b2a14e5" xlink:to="loc_trs_LineOfCreditBorrowingCapacityConsideringCovenantRestrictions_7d8e48bb-65d5-4afe-9bb8-2ddd7e15804d" xlink:type="arc" order="15"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/LongtermDebtOtherRevolvingLoanFacilityDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#LongtermDebtOtherRevolvingLoanFacilityDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/LongtermDebtOtherRevolvingLoanFacilityDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_6500fa25-2012-4d43-a6f5-1a0ca2b1a7f3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_9b706571-f29f-4311-ace0-98a0107878e7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6500fa25-2012-4d43-a6f5-1a0ca2b1a7f3" xlink:to="loc_us-gaap_DebtInstrumentTable_9b706571-f29f-4311-ace0-98a0107878e7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_48deced9-87fe-4f46-8410-d59fb7da958e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9b706571-f29f-4311-ace0-98a0107878e7" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_48deced9-87fe-4f46-8410-d59fb7da958e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_48deced9-87fe-4f46-8410-d59fb7da958e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_48deced9-87fe-4f46-8410-d59fb7da958e" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_48deced9-87fe-4f46-8410-d59fb7da958e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_af222d5f-34f7-4c74-bd81-9cea70c25d20" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_48deced9-87fe-4f46-8410-d59fb7da958e" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_af222d5f-34f7-4c74-bd81-9cea70c25d20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_ce91aa5c-3449-4a19-ae59-08dfb9704683" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_af222d5f-34f7-4c74-bd81-9cea70c25d20" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_ce91aa5c-3449-4a19-ae59-08dfb9704683" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_b4ca6a8c-892f-442d-9704-19ff9d5dfb6d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9b706571-f29f-4311-ace0-98a0107878e7" xlink:to="loc_us-gaap_DebtInstrumentAxis_b4ca6a8c-892f-442d-9704-19ff9d5dfb6d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_b4ca6a8c-892f-442d-9704-19ff9d5dfb6d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_b4ca6a8c-892f-442d-9704-19ff9d5dfb6d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_b4ca6a8c-892f-442d-9704-19ff9d5dfb6d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_6fb9ca21-05c3-4823-a3bb-e34de3ee58f2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_b4ca6a8c-892f-442d-9704-19ff9d5dfb6d" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_6fb9ca21-05c3-4823-a3bb-e34de3ee58f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_fc88fbdd-676a-4f3f-9d27-e883fec4e206" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_6fb9ca21-05c3-4823-a3bb-e34de3ee58f2" xlink:to="loc_us-gaap_NonUsMember_fc88fbdd-676a-4f3f-9d27-e883fec4e206" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_ab69c339-f912-47d0-ad66-2f5858ab920d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6500fa25-2012-4d43-a6f5-1a0ca2b1a7f3" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_ab69c339-f912-47d0-ad66-2f5858ab920d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_3f8b34e2-6a46-49e5-939b-0d900c5e2bc2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_6500fa25-2012-4d43-a6f5-1a0ca2b1a7f3" xlink:to="loc_us-gaap_LineOfCredit_3f8b34e2-6a46-49e5-939b-0d900c5e2bc2" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/LongtermDebtFairValueDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#LongtermDebtFairValueDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/LongtermDebtFairValueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_cfc14440-6bdb-4ace-bde3-a50c19aa49fa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ScheduleOfDebtInstrumentsTable_851d2aed-2856-467c-a302-bf76b9b35e1c" xlink:href="trs-20241231.xsd#trs_ScheduleOfDebtInstrumentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_cfc14440-6bdb-4ace-bde3-a50c19aa49fa" xlink:to="loc_trs_ScheduleOfDebtInstrumentsTable_851d2aed-2856-467c-a302-bf76b9b35e1c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_cb514b72-fd7c-4e0e-a32a-67127d7a8b16" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfDebtInstrumentsTable_851d2aed-2856-467c-a302-bf76b9b35e1c" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_cb514b72-fd7c-4e0e-a32a-67127d7a8b16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_cb514b72-fd7c-4e0e-a32a-67127d7a8b16_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_cb514b72-fd7c-4e0e-a32a-67127d7a8b16" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_cb514b72-fd7c-4e0e-a32a-67127d7a8b16_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_001a20be-934b-4259-b2db-99c824d1261a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_cb514b72-fd7c-4e0e-a32a-67127d7a8b16" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_001a20be-934b-4259-b2db-99c824d1261a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_b0549bd4-a859-4864-8044-52742d832009" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_001a20be-934b-4259-b2db-99c824d1261a" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_b0549bd4-a859-4864-8044-52742d832009" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_621ff045-d872-4f59-a0e3-c733550ef444" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfDebtInstrumentsTable_851d2aed-2856-467c-a302-bf76b9b35e1c" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_621ff045-d872-4f59-a0e3-c733550ef444" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_621ff045-d872-4f59-a0e3-c733550ef444_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_621ff045-d872-4f59-a0e3-c733550ef444" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_621ff045-d872-4f59-a0e3-c733550ef444_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_7e016f55-a98f-4b94-b94d-52e5248deb08" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_621ff045-d872-4f59-a0e3-c733550ef444" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_7e016f55-a98f-4b94-b94d-52e5248deb08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_SeniorSecuredTermLoanMember_444bdcdb-2022-48bb-9ee9-bc35446b066c" xlink:href="trs-20241231.xsd#trs_SeniorSecuredTermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_7e016f55-a98f-4b94-b94d-52e5248deb08" xlink:to="loc_trs_SeniorSecuredTermLoanMember_444bdcdb-2022-48bb-9ee9-bc35446b066c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_14275925-6085-4026-a17b-48f1160564c7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfDebtInstrumentsTable_851d2aed-2856-467c-a302-bf76b9b35e1c" xlink:to="loc_us-gaap_CreditFacilityAxis_14275925-6085-4026-a17b-48f1160564c7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_14275925-6085-4026-a17b-48f1160564c7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_14275925-6085-4026-a17b-48f1160564c7" xlink:to="loc_us-gaap_CreditFacilityDomain_14275925-6085-4026-a17b-48f1160564c7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_ca617424-2e95-4549-933e-2ff3415b3b8b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_14275925-6085-4026-a17b-48f1160564c7" xlink:to="loc_us-gaap_CreditFacilityDomain_ca617424-2e95-4549-933e-2ff3415b3b8b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_ae1204c3-0066-44a6-b671-01904d898860" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_ca617424-2e95-4549-933e-2ff3415b3b8b" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_ae1204c3-0066-44a6-b671-01904d898860" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_069fdd9b-be0e-4ca2-b5bc-0f2d398abd46" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfDebtInstrumentsTable_851d2aed-2856-467c-a302-bf76b9b35e1c" xlink:to="loc_us-gaap_DebtInstrumentAxis_069fdd9b-be0e-4ca2-b5bc-0f2d398abd46" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_069fdd9b-be0e-4ca2-b5bc-0f2d398abd46_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_069fdd9b-be0e-4ca2-b5bc-0f2d398abd46" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_069fdd9b-be0e-4ca2-b5bc-0f2d398abd46_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_df6a2611-b030-46c8-8404-847220d6e033" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_069fdd9b-be0e-4ca2-b5bc-0f2d398abd46" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_df6a2611-b030-46c8-8404-847220d6e033" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_CreditAgreementMember_6cfd893c-3a93-43b2-91d9-a7995c71ae82" xlink:href="trs-20241231.xsd#trs_CreditAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_df6a2611-b030-46c8-8404-847220d6e033" xlink:to="loc_trs_CreditAgreementMember_6cfd893c-3a93-43b2-91d9-a7995c71ae82" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_5b5ac142-c0dc-407e-8109-b3f5091fd247" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_df6a2611-b030-46c8-8404-847220d6e033" xlink:to="loc_us-gaap_SeniorNotesMember_5b5ac142-c0dc-407e-8109-b3f5091fd247" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_A4125SeniorUnsecuredNotesDue2029Member_1637ba97-2276-4640-a67a-6b954dddc25c" xlink:href="trs-20241231.xsd#trs_A4125SeniorUnsecuredNotesDue2029Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_df6a2611-b030-46c8-8404-847220d6e033" xlink:to="loc_trs_A4125SeniorUnsecuredNotesDue2029Member_1637ba97-2276-4640-a67a-6b954dddc25c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_A4.875SeniorUnsecuredNotesDue2025Member_9aadbb31-c352-44be-ad90-85f0ad65887f" xlink:href="trs-20241231.xsd#trs_A4.875SeniorUnsecuredNotesDue2025Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_df6a2611-b030-46c8-8404-847220d6e033" xlink:to="loc_trs_A4.875SeniorUnsecuredNotesDue2025Member_9aadbb31-c352-44be-ad90-85f0ad65887f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtAndCapitalLeaseObligations_6030c9eb-f998-4c4a-a9a6-53fd13c6696c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtAndCapitalLeaseObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_cfc14440-6bdb-4ace-bde3-a50c19aa49fa" xlink:to="loc_us-gaap_DebtAndCapitalLeaseObligations_6030c9eb-f998-4c4a-a9a6-53fd13c6696c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_73812f36-431d-4915-9743-f886b19de130" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_cfc14440-6bdb-4ace-bde3-a50c19aa49fa" xlink:to="loc_us-gaap_LongTermDebtFairValue_73812f36-431d-4915-9743-f886b19de130" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/LongtermDebtDebtIssuanceCostsDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#LongtermDebtDebtIssuanceCostsDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/LongtermDebtDebtIssuanceCostsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_c7d43f09-97eb-4127-a533-d95a4a401549" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_0383b3ad-a15b-4c17-8e96-e3cc2a1bc75f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c7d43f09-97eb-4127-a533-d95a4a401549" xlink:to="loc_us-gaap_DebtInstrumentTable_0383b3ad-a15b-4c17-8e96-e3cc2a1bc75f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_8f394b11-db17-4667-9b20-93dd98b9a492" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_0383b3ad-a15b-4c17-8e96-e3cc2a1bc75f" xlink:to="loc_us-gaap_DebtInstrumentAxis_8f394b11-db17-4667-9b20-93dd98b9a492" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_8f394b11-db17-4667-9b20-93dd98b9a492_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_8f394b11-db17-4667-9b20-93dd98b9a492" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_8f394b11-db17-4667-9b20-93dd98b9a492_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_7efe9de9-e37b-408f-9354-1363dcc69427" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_8f394b11-db17-4667-9b20-93dd98b9a492" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_7efe9de9-e37b-408f-9354-1363dcc69427" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_2699c28d-a16c-4e9e-94e5-aa136750fe5f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c7d43f09-97eb-4127-a533-d95a4a401549" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_2699c28d-a16c-4e9e-94e5-aa136750fe5f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts_12f107c7-95cb-4ad8-ae46-4b39bc9a8b39" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AmortizationOfFinancingCostsAndDiscounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_c7d43f09-97eb-4127-a533-d95a4a401549" xlink:to="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts_12f107c7-95cb-4ad8-ae46-4b39bc9a8b39" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/DerivativeInstrumentsDerivativeNarrativeDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#DerivativeInstrumentsDerivativeNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DerivativeInstrumentsDerivativeNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_319b9b96-f834-43be-8cd5-529c751a18e9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_0bfbe7f5-a673-43c5-bdd4-f22b5d65bb3f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_319b9b96-f834-43be-8cd5-529c751a18e9" xlink:to="loc_us-gaap_DerivativeTable_0bfbe7f5-a673-43c5-bdd4-f22b5d65bb3f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_79503ffe-e1ff-4ff0-8608-7d7579bf355b" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_0bfbe7f5-a673-43c5-bdd4-f22b5d65bb3f" xlink:to="loc_srt_RangeAxis_79503ffe-e1ff-4ff0-8608-7d7579bf355b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_79503ffe-e1ff-4ff0-8608-7d7579bf355b_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_79503ffe-e1ff-4ff0-8608-7d7579bf355b" xlink:to="loc_srt_RangeMember_79503ffe-e1ff-4ff0-8608-7d7579bf355b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_a2b27e9a-ca12-422d-90b0-44185048c2ed" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_79503ffe-e1ff-4ff0-8608-7d7579bf355b" xlink:to="loc_srt_RangeMember_a2b27e9a-ca12-422d-90b0-44185048c2ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_d8f165bb-e681-49af-aef4-3f7274db784d" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_a2b27e9a-ca12-422d-90b0-44185048c2ed" xlink:to="loc_srt_MaximumMember_d8f165bb-e681-49af-aef4-3f7274db784d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_e1246f5a-bde3-4291-bace-6a19dc32469d" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_a2b27e9a-ca12-422d-90b0-44185048c2ed" xlink:to="loc_srt_MinimumMember_e1246f5a-bde3-4291-bace-6a19dc32469d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_2254c18b-1564-40c6-8e18-87b392add17c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_0bfbe7f5-a673-43c5-bdd4-f22b5d65bb3f" xlink:to="loc_us-gaap_HedgingDesignationAxis_2254c18b-1564-40c6-8e18-87b392add17c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_2254c18b-1564-40c6-8e18-87b392add17c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_2254c18b-1564-40c6-8e18-87b392add17c" xlink:to="loc_us-gaap_HedgingDesignationDomain_2254c18b-1564-40c6-8e18-87b392add17c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_a35c044c-9d8b-4a20-a07f-111b14c3c65d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_2254c18b-1564-40c6-8e18-87b392add17c" xlink:to="loc_us-gaap_HedgingDesignationDomain_a35c044c-9d8b-4a20-a07f-111b14c3c65d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_81ca42ab-200f-44a3-b7b0-68c4037329fa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_a35c044c-9d8b-4a20-a07f-111b14c3c65d" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_81ca42ab-200f-44a3-b7b0-68c4037329fa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_86e54055-5fe1-40d0-b482-4ef53175923f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_a35c044c-9d8b-4a20-a07f-111b14c3c65d" xlink:to="loc_us-gaap_NondesignatedMember_86e54055-5fe1-40d0-b482-4ef53175923f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_601c35af-657d-4202-8c0c-f0078475c6df" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_0bfbe7f5-a673-43c5-bdd4-f22b5d65bb3f" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_601c35af-657d-4202-8c0c-f0078475c6df" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_601c35af-657d-4202-8c0c-f0078475c6df_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_601c35af-657d-4202-8c0c-f0078475c6df" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_601c35af-657d-4202-8c0c-f0078475c6df_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_58849041-0c76-4476-899e-2137312b4c8d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_601c35af-657d-4202-8c0c-f0078475c6df" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_58849041-0c76-4476-899e-2137312b4c8d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CrossCurrencyInterestRateContractMember_df1101ba-71a7-4917-a057-2e2be29eda6b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CrossCurrencyInterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_58849041-0c76-4476-899e-2137312b4c8d" xlink:to="loc_us-gaap_CrossCurrencyInterestRateContractMember_df1101ba-71a7-4917-a057-2e2be29eda6b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_1bd3c6af-97b6-48f8-96cb-4e929cbf3e46" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_58849041-0c76-4476-899e-2137312b4c8d" xlink:to="loc_us-gaap_ForeignExchangeContractMember_1bd3c6af-97b6-48f8-96cb-4e929cbf3e46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_b51dc499-5082-43c2-8209-196c2765b029" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_0bfbe7f5-a673-43c5-bdd4-f22b5d65bb3f" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_b51dc499-5082-43c2-8209-196c2765b029" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_b51dc499-5082-43c2-8209-196c2765b029_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_b51dc499-5082-43c2-8209-196c2765b029" xlink:to="loc_us-gaap_HedgingRelationshipDomain_b51dc499-5082-43c2-8209-196c2765b029_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_30fa824c-be47-4b63-984b-6d35a4010d6d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_b51dc499-5082-43c2-8209-196c2765b029" xlink:to="loc_us-gaap_HedgingRelationshipDomain_30fa824c-be47-4b63-984b-6d35a4010d6d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetInvestmentHedgingMember_a0b6ec8d-1223-4311-b840-041c7fc91f39" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetInvestmentHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_30fa824c-be47-4b63-984b-6d35a4010d6d" xlink:to="loc_us-gaap_NetInvestmentHedgingMember_a0b6ec8d-1223-4311-b840-041c7fc91f39" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DerivativeContractDateAxis_b61143be-6db0-4594-ae84-6497fa356020" xlink:href="trs-20241231.xsd#trs_DerivativeContractDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_0bfbe7f5-a673-43c5-bdd4-f22b5d65bb3f" xlink:to="loc_trs_DerivativeContractDateAxis_b61143be-6db0-4594-ae84-6497fa356020" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DerivativeContractDateDomain_b61143be-6db0-4594-ae84-6497fa356020_default" xlink:href="trs-20241231.xsd#trs_DerivativeContractDateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_DerivativeContractDateAxis_b61143be-6db0-4594-ae84-6497fa356020" xlink:to="loc_trs_DerivativeContractDateDomain_b61143be-6db0-4594-ae84-6497fa356020_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DerivativeContractDateDomain_e26f9fcc-0790-4921-bc28-fd65470ec963" xlink:href="trs-20241231.xsd#trs_DerivativeContractDateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_DerivativeContractDateAxis_b61143be-6db0-4594-ae84-6497fa356020" xlink:to="loc_trs_DerivativeContractDateDomain_e26f9fcc-0790-4921-bc28-fd65470ec963" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_October2018CrossCurrencySwapMember_be10753c-ea00-489c-9cf3-47f746d38f6c" xlink:href="trs-20241231.xsd#trs_October2018CrossCurrencySwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DerivativeContractDateDomain_e26f9fcc-0790-4921-bc28-fd65470ec963" xlink:to="loc_trs_October2018CrossCurrencySwapMember_be10753c-ea00-489c-9cf3-47f746d38f6c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_November2020CrossCurrencySwapMember_d1154354-7633-4132-8861-9c7b88d40abd" xlink:href="trs-20241231.xsd#trs_November2020CrossCurrencySwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DerivativeContractDateDomain_e26f9fcc-0790-4921-bc28-fd65470ec963" xlink:to="loc_trs_November2020CrossCurrencySwapMember_d1154354-7633-4132-8861-9c7b88d40abd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_February2024DerivativeContractDateDomain_5016273e-b2fe-4e85-a46f-1cebad9b50fb" xlink:href="trs-20241231.xsd#trs_February2024DerivativeContractDateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DerivativeContractDateDomain_e26f9fcc-0790-4921-bc28-fd65470ec963" xlink:to="loc_trs_February2024DerivativeContractDateDomain_5016273e-b2fe-4e85-a46f-1cebad9b50fb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_June2024DerivativeDomain_61d3b3a6-4b8f-4e0e-b2aa-46e9bde9a9fb" xlink:href="trs-20241231.xsd#trs_June2024DerivativeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DerivativeContractDateDomain_e26f9fcc-0790-4921-bc28-fd65470ec963" xlink:to="loc_trs_June2024DerivativeDomain_61d3b3a6-4b8f-4e0e-b2aa-46e9bde9a9fb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_cabd6c06-dc09-429a-8a43-8bee5c0755a8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_319b9b96-f834-43be-8cd5-529c751a18e9" xlink:to="loc_us-gaap_DerivativeNotionalAmount_cabd6c06-dc09-429a-8a43-8bee5c0755a8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeCashReceivedOnHedge_93fbbedf-9885-4378-90a2-7bf78a9800f7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeCashReceivedOnHedge"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_319b9b96-f834-43be-8cd5-529c751a18e9" xlink:to="loc_us-gaap_DerivativeCashReceivedOnHedge_93fbbedf-9885-4378-90a2-7bf78a9800f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFixedInterestRate_3fd18c8b-deff-45a7-a1c9-657dc197f605" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeFixedInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_319b9b96-f834-43be-8cd5-529c751a18e9" xlink:to="loc_us-gaap_DerivativeFixedInterestRate_3fd18c8b-deff-45a7-a1c9-657dc197f605" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeNet_b3c48eed-4f39-415e-b65e-423c506f7258" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeFairValueOfDerivativeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_319b9b96-f834-43be-8cd5-529c751a18e9" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeNet_b3c48eed-4f39-415e-b65e-423c506f7258" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/DerivativeInstrumentsDesignatedashedgingFinancialPositionDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#DerivativeInstrumentsDesignatedashedgingFinancialPositionDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DerivativeInstrumentsDesignatedashedgingFinancialPositionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_08e38c15-3791-43f9-b6f8-4b38f91f117b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_c881fde4-44bd-4c10-a17f-28ec267cd3d3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_08e38c15-3791-43f9-b6f8-4b38f91f117b" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_c881fde4-44bd-4c10-a17f-28ec267cd3d3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_96f62011-157e-4c23-9a1e-d9be479e9e5e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_c881fde4-44bd-4c10-a17f-28ec267cd3d3" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_96f62011-157e-4c23-9a1e-d9be479e9e5e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_96f62011-157e-4c23-9a1e-d9be479e9e5e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_96f62011-157e-4c23-9a1e-d9be479e9e5e" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_96f62011-157e-4c23-9a1e-d9be479e9e5e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_5115b1c7-7cc2-41a2-881a-3d1859f45658" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_96f62011-157e-4c23-9a1e-d9be479e9e5e" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_5115b1c7-7cc2-41a2-881a-3d1859f45658" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CrossCurrencyInterestRateContractMember_89cb3d21-32ef-4fae-aaf1-5aff82102ba3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CrossCurrencyInterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_5115b1c7-7cc2-41a2-881a-3d1859f45658" xlink:to="loc_us-gaap_CrossCurrencyInterestRateContractMember_89cb3d21-32ef-4fae-aaf1-5aff82102ba3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_58fe5082-ba2d-4960-a1a4-9a99ecdc78b2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_5115b1c7-7cc2-41a2-881a-3d1859f45658" xlink:to="loc_us-gaap_InterestRateSwapMember_58fe5082-ba2d-4960-a1a4-9a99ecdc78b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_0770ce45-98b5-472e-8ec5-c87ab28bfbde" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_c881fde4-44bd-4c10-a17f-28ec267cd3d3" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_0770ce45-98b5-472e-8ec5-c87ab28bfbde" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_0770ce45-98b5-472e-8ec5-c87ab28bfbde_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_0770ce45-98b5-472e-8ec5-c87ab28bfbde" xlink:to="loc_us-gaap_HedgingRelationshipDomain_0770ce45-98b5-472e-8ec5-c87ab28bfbde_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_4cedca3f-abe4-4f8a-8589-dae796d46a92" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_0770ce45-98b5-472e-8ec5-c87ab28bfbde" xlink:to="loc_us-gaap_HedgingRelationshipDomain_4cedca3f-abe4-4f8a-8589-dae796d46a92" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_13d14a30-6aa9-44f0-bef1-e2947f5ea4ea" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_4cedca3f-abe4-4f8a-8589-dae796d46a92" xlink:to="loc_us-gaap_CashFlowHedgingMember_13d14a30-6aa9-44f0-bef1-e2947f5ea4ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetInvestmentHedgingMember_99804471-e16d-42b0-9f52-e05706594652" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetInvestmentHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_4cedca3f-abe4-4f8a-8589-dae796d46a92" xlink:to="loc_us-gaap_NetInvestmentHedgingMember_99804471-e16d-42b0-9f52-e05706594652" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_62395da3-2607-47dd-a66c-410aef83a2a3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_c881fde4-44bd-4c10-a17f-28ec267cd3d3" xlink:to="loc_us-gaap_HedgingDesignationAxis_62395da3-2607-47dd-a66c-410aef83a2a3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_62395da3-2607-47dd-a66c-410aef83a2a3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_62395da3-2607-47dd-a66c-410aef83a2a3" xlink:to="loc_us-gaap_HedgingDesignationDomain_62395da3-2607-47dd-a66c-410aef83a2a3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_87eba6b1-35ca-466d-b913-9109f32838d3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_62395da3-2607-47dd-a66c-410aef83a2a3" xlink:to="loc_us-gaap_HedgingDesignationDomain_87eba6b1-35ca-466d-b913-9109f32838d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_d6cd69fa-b295-492b-8b59-9c571637a207" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_87eba6b1-35ca-466d-b913-9109f32838d3" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_d6cd69fa-b295-492b-8b59-9c571637a207" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_9f79e68c-c24d-4b8f-8e5e-5e66de42763e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_c881fde4-44bd-4c10-a17f-28ec267cd3d3" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_9f79e68c-c24d-4b8f-8e5e-5e66de42763e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_9f79e68c-c24d-4b8f-8e5e-5e66de42763e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_9f79e68c-c24d-4b8f-8e5e-5e66de42763e" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_9f79e68c-c24d-4b8f-8e5e-5e66de42763e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_c0f123d2-8be9-4061-a050-3f91c7058abb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_9f79e68c-c24d-4b8f-8e5e-5e66de42763e" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_c0f123d2-8be9-4061-a050-3f91c7058abb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember_25492ef1-a71d-41af-b11c-4e5778ca0bc3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_c0f123d2-8be9-4061-a050-3f91c7058abb" xlink:to="loc_us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember_25492ef1-a71d-41af-b11c-4e5778ca0bc3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsMember_7661b2c9-4624-4497-8d51-815961641598" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_c0f123d2-8be9-4061-a050-3f91c7058abb" xlink:to="loc_us-gaap_OtherAssetsMember_7661b2c9-4624-4497-8d51-815961641598" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccruedLiabilitiesMember_fc141997-7fc6-4db7-bce0-dc66004461a7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccruedLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_c0f123d2-8be9-4061-a050-3f91c7058abb" xlink:to="loc_us-gaap_AccruedLiabilitiesMember_fc141997-7fc6-4db7-bce0-dc66004461a7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesMember_ccb28e5b-324b-4442-b260-ed3e53bfdc97" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_c0f123d2-8be9-4061-a050-3f91c7058abb" xlink:to="loc_us-gaap_OtherLiabilitiesMember_ccb28e5b-324b-4442-b260-ed3e53bfdc97" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral_bf9e56d0-f370-49d1-b5d6-ffff089025f9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_08e38c15-3791-43f9-b6f8-4b38f91f117b" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral_bf9e56d0-f370-49d1-b5d6-ffff089025f9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral_bb791cc5-0e28-4ce2-94cd-828e3fa2417a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_08e38c15-3791-43f9-b6f8-4b38f91f117b" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral_bb791cc5-0e28-4ce2-94cd-828e3fa2417a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/DerivativeInstrumentsDesignatedashedgingFinancialPerformanceDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#DerivativeInstrumentsDesignatedashedgingFinancialPerformanceDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DerivativeInstrumentsDesignatedashedgingFinancialPerformanceDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_5355817b-c3bb-481b-b00d-a05ba1c48109" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_328391fe-3fc7-447e-ab21-8e351441d67b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_5355817b-c3bb-481b-b00d-a05ba1c48109" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_328391fe-3fc7-447e-ab21-8e351441d67b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_c0299bca-5ee1-4e42-8248-9874c0d712b4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_328391fe-3fc7-447e-ab21-8e351441d67b" xlink:to="loc_us-gaap_HedgingDesignationAxis_c0299bca-5ee1-4e42-8248-9874c0d712b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_c0299bca-5ee1-4e42-8248-9874c0d712b4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_c0299bca-5ee1-4e42-8248-9874c0d712b4" xlink:to="loc_us-gaap_HedgingDesignationDomain_c0299bca-5ee1-4e42-8248-9874c0d712b4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_d01318f2-0814-418f-86fc-505689b4d576" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_c0299bca-5ee1-4e42-8248-9874c0d712b4" xlink:to="loc_us-gaap_HedgingDesignationDomain_d01318f2-0814-418f-86fc-505689b4d576" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_44bd8efd-013d-4b7c-b0c6-31a8e132a94e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_d01318f2-0814-418f-86fc-505689b4d576" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_44bd8efd-013d-4b7c-b0c6-31a8e132a94e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_6611997b-420b-41cc-b618-2471b71d63a6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_328391fe-3fc7-447e-ab21-8e351441d67b" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_6611997b-420b-41cc-b618-2471b71d63a6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_6611997b-420b-41cc-b618-2471b71d63a6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_6611997b-420b-41cc-b618-2471b71d63a6" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_6611997b-420b-41cc-b618-2471b71d63a6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_88e37f9a-ab52-4752-8f9c-301fb925d506" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_6611997b-420b-41cc-b618-2471b71d63a6" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_88e37f9a-ab52-4752-8f9c-301fb925d506" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CrossCurrencyInterestRateContractMember_d67fd492-316c-4782-986c-e2b12e2099f8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CrossCurrencyInterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_88e37f9a-ab52-4752-8f9c-301fb925d506" xlink:to="loc_us-gaap_CrossCurrencyInterestRateContractMember_d67fd492-316c-4782-986c-e2b12e2099f8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_405f79a3-b96c-478f-bc95-475dd5c67ae7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_88e37f9a-ab52-4752-8f9c-301fb925d506" xlink:to="loc_us-gaap_InterestRateSwapMember_405f79a3-b96c-478f-bc95-475dd5c67ae7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_a38fd3ba-53ec-4383-abaa-199980d30750" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_328391fe-3fc7-447e-ab21-8e351441d67b" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_a38fd3ba-53ec-4383-abaa-199980d30750" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_a38fd3ba-53ec-4383-abaa-199980d30750_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_a38fd3ba-53ec-4383-abaa-199980d30750" xlink:to="loc_us-gaap_HedgingRelationshipDomain_a38fd3ba-53ec-4383-abaa-199980d30750_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_91f91925-e5c0-4312-a434-ba6011af8a6e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_a38fd3ba-53ec-4383-abaa-199980d30750" xlink:to="loc_us-gaap_HedgingRelationshipDomain_91f91925-e5c0-4312-a434-ba6011af8a6e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetInvestmentHedgingMember_80836e7c-c2c7-4a02-8ea8-9c2e8174ac76" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetInvestmentHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_91f91925-e5c0-4312-a434-ba6011af8a6e" xlink:to="loc_us-gaap_NetInvestmentHedgingMember_80836e7c-c2c7-4a02-8ea8-9c2e8174ac76" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_770ea9ee-54a0-4ddd-a9f6-ee92a2277b12" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_91f91925-e5c0-4312-a434-ba6011af8a6e" xlink:to="loc_us-gaap_CashFlowHedgingMember_770ea9ee-54a0-4ddd-a9f6-ee92a2277b12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_a93f890f-7789-4ba6-83ee-e129437e60d5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_328391fe-3fc7-447e-ab21-8e351441d67b" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_a93f890f-7789-4ba6-83ee-e129437e60d5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_a93f890f-7789-4ba6-83ee-e129437e60d5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_a93f890f-7789-4ba6-83ee-e129437e60d5" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_a93f890f-7789-4ba6-83ee-e129437e60d5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_e95b4e7f-b25c-4d14-bfff-2d6e55fa2cae" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_a93f890f-7789-4ba6-83ee-e129437e60d5" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_e95b4e7f-b25c-4d14-bfff-2d6e55fa2cae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseMember_3b89ff04-127a-413e-a6bc-c1ca263b746c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_e95b4e7f-b25c-4d14-bfff-2d6e55fa2cae" xlink:to="loc_us-gaap_InterestExpenseMember_3b89ff04-127a-413e-a6bc-c1ca263b746c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DebtfinancingandrelatedexpensesMember_090992ad-644d-4914-8f80-0484dd21dbc0" xlink:href="trs-20241231.xsd#trs_DebtfinancingandrelatedexpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_e95b4e7f-b25c-4d14-bfff-2d6e55fa2cae" xlink:to="loc_trs_DebtfinancingandrelatedexpensesMember_090992ad-644d-4914-8f80-0484dd21dbc0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_686df8d1-2abb-4223-81ba-873f05cf69f2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_5355817b-c3bb-481b-b00d-a05ba1c48109" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_686df8d1-2abb-4223-81ba-873f05cf69f2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_29a95fab-2f9a-4ce1-8549-4b1e097fccf7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_5355817b-c3bb-481b-b00d-a05ba1c48109" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_29a95fab-2f9a-4ce1-8549-4b1e097fccf7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimateOfTimeToTransfer1_402d0f91-a29e-46e4-901f-6723c477e666" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimateOfTimeToTransfer1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_5355817b-c3bb-481b-b00d-a05ba1c48109" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimateOfTimeToTransfer1_402d0f91-a29e-46e4-901f-6723c477e666" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred_af5c1de2-7281-4e56-b9ee-e62c12d2bc2b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_5355817b-c3bb-481b-b00d-a05ba1c48109" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred_af5c1de2-7281-4e56-b9ee-e62c12d2bc2b" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/DerivativeInstrumentsDerivativesnotdesignatedashedginginstrumentsDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#DerivativeInstrumentsDerivativesnotdesignatedashedginginstrumentsDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DerivativeInstrumentsDerivativesnotdesignatedashedginginstrumentsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_56b522ea-2025-43aa-91d4-0cca0353f048" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_d90d23c7-bd44-46fc-9543-945ed3a45316" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_56b522ea-2025-43aa-91d4-0cca0353f048" xlink:to="loc_us-gaap_DerivativeTable_d90d23c7-bd44-46fc-9543-945ed3a45316" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_196471fd-c588-4097-8e39-080f0abc92d0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_d90d23c7-bd44-46fc-9543-945ed3a45316" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_196471fd-c588-4097-8e39-080f0abc92d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_196471fd-c588-4097-8e39-080f0abc92d0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_196471fd-c588-4097-8e39-080f0abc92d0" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_196471fd-c588-4097-8e39-080f0abc92d0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_7ccbe06e-56aa-4157-b60d-1fc7e6a1e7c9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_196471fd-c588-4097-8e39-080f0abc92d0" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_7ccbe06e-56aa-4157-b60d-1fc7e6a1e7c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpenseMember_fe1699d7-201a-407b-9d17-5da080c830d5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherNonoperatingIncomeExpenseMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_7ccbe06e-56aa-4157-b60d-1fc7e6a1e7c9" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpenseMember_fe1699d7-201a-407b-9d17-5da080c830d5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_6f46315b-6c22-4989-ae5e-2d5c76a770a3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_d90d23c7-bd44-46fc-9543-945ed3a45316" xlink:to="loc_us-gaap_HedgingDesignationAxis_6f46315b-6c22-4989-ae5e-2d5c76a770a3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_6f46315b-6c22-4989-ae5e-2d5c76a770a3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_6f46315b-6c22-4989-ae5e-2d5c76a770a3" xlink:to="loc_us-gaap_HedgingDesignationDomain_6f46315b-6c22-4989-ae5e-2d5c76a770a3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_ed3201f9-4371-4198-8d8f-20b4c78d5388" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_6f46315b-6c22-4989-ae5e-2d5c76a770a3" xlink:to="loc_us-gaap_HedgingDesignationDomain_ed3201f9-4371-4198-8d8f-20b4c78d5388" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_a0176f97-7c37-45c0-b546-4e1392f7e371" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_ed3201f9-4371-4198-8d8f-20b4c78d5388" xlink:to="loc_us-gaap_NondesignatedMember_a0176f97-7c37-45c0-b546-4e1392f7e371" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_3c2451e8-dd41-4e74-96b6-71004a52dd68" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_d90d23c7-bd44-46fc-9543-945ed3a45316" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_3c2451e8-dd41-4e74-96b6-71004a52dd68" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_3c2451e8-dd41-4e74-96b6-71004a52dd68_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_3c2451e8-dd41-4e74-96b6-71004a52dd68" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_3c2451e8-dd41-4e74-96b6-71004a52dd68_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_1576ef3f-56be-4a2a-bdee-09e50df1366f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_3c2451e8-dd41-4e74-96b6-71004a52dd68" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_1576ef3f-56be-4a2a-bdee-09e50df1366f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_884d4b5a-50d7-4384-8c15-53a3086b47f4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_1576ef3f-56be-4a2a-bdee-09e50df1366f" xlink:to="loc_us-gaap_ForeignExchangeContractMember_884d4b5a-50d7-4384-8c15-53a3086b47f4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrencySwapMember_ee228b57-6ab6-48e2-aae0-0c24b080bb46" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CurrencySwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_1576ef3f-56be-4a2a-bdee-09e50df1366f" xlink:to="loc_us-gaap_CurrencySwapMember_ee228b57-6ab6-48e2-aae0-0c24b080bb46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CrossCurrencyInterestRateContractMember_015cd30b-9367-47aa-a041-1cea3c71f5d9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CrossCurrencyInterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_1576ef3f-56be-4a2a-bdee-09e50df1366f" xlink:to="loc_us-gaap_CrossCurrencyInterestRateContractMember_015cd30b-9367-47aa-a041-1cea3c71f5d9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_47992738-f2b8-402b-ae02-862af220ae61" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_56b522ea-2025-43aa-91d4-0cca0353f048" xlink:to="loc_us-gaap_DerivativeNotionalAmount_47992738-f2b8-402b-ae02-862af220ae61" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnForeignCurrencyDerivativesRecordedInEarningsNet_b45b8c51-6829-4ae6-97b9-a19ad86a989c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GainLossOnForeignCurrencyDerivativesRecordedInEarningsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_56b522ea-2025-43aa-91d4-0cca0353f048" xlink:to="loc_us-gaap_GainLossOnForeignCurrencyDerivativesRecordedInEarningsNet_b45b8c51-6829-4ae6-97b9-a19ad86a989c" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/DerivativeInstrumentsFairValueMeasurementsDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#DerivativeInstrumentsFairValueMeasurementsDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DerivativeInstrumentsFairValueMeasurementsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_09a89424-2a6f-44a5-9f9d-527bab6dda89" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_e2d9c1bf-3bba-4afb-9c85-3dbc4e9f3dc3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_09a89424-2a6f-44a5-9f9d-527bab6dda89" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_e2d9c1bf-3bba-4afb-9c85-3dbc4e9f3dc3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_a514192c-38fd-4e43-8f77-d6b51de20ca3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_e2d9c1bf-3bba-4afb-9c85-3dbc4e9f3dc3" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_a514192c-38fd-4e43-8f77-d6b51de20ca3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_a514192c-38fd-4e43-8f77-d6b51de20ca3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_a514192c-38fd-4e43-8f77-d6b51de20ca3" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_a514192c-38fd-4e43-8f77-d6b51de20ca3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_3031001b-7830-4acd-9364-56122e5e95e2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_a514192c-38fd-4e43-8f77-d6b51de20ca3" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_3031001b-7830-4acd-9364-56122e5e95e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CrossCurrencyInterestRateContractMember_4efa1a8b-5255-4929-8a4b-c854ba7a6e32" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CrossCurrencyInterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_3031001b-7830-4acd-9364-56122e5e95e2" xlink:to="loc_us-gaap_CrossCurrencyInterestRateContractMember_4efa1a8b-5255-4929-8a4b-c854ba7a6e32" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_fd0f5730-cea7-4ad5-83dd-7fc45715b6b3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_3031001b-7830-4acd-9364-56122e5e95e2" xlink:to="loc_us-gaap_ForeignExchangeContractMember_fd0f5730-cea7-4ad5-83dd-7fc45715b6b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_233484a6-b9b1-40f9-bfc6-379dc4ab3539" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_e2d9c1bf-3bba-4afb-9c85-3dbc4e9f3dc3" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_233484a6-b9b1-40f9-bfc6-379dc4ab3539" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_233484a6-b9b1-40f9-bfc6-379dc4ab3539_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_233484a6-b9b1-40f9-bfc6-379dc4ab3539" xlink:to="loc_us-gaap_HedgingRelationshipDomain_233484a6-b9b1-40f9-bfc6-379dc4ab3539_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_e3dd9f02-5157-45b6-9d6e-b83515fd16fa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_233484a6-b9b1-40f9-bfc6-379dc4ab3539" xlink:to="loc_us-gaap_HedgingRelationshipDomain_e3dd9f02-5157-45b6-9d6e-b83515fd16fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetInvestmentHedgingMember_e180c25e-bd1e-490e-a358-4cfe382e0fb1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NetInvestmentHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_e3dd9f02-5157-45b6-9d6e-b83515fd16fa" xlink:to="loc_us-gaap_NetInvestmentHedgingMember_e180c25e-bd1e-490e-a358-4cfe382e0fb1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_d61b369c-af61-445c-958a-2f523f855f1a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_e2d9c1bf-3bba-4afb-9c85-3dbc4e9f3dc3" xlink:to="loc_us-gaap_FinancialInstrumentAxis_d61b369c-af61-445c-958a-2f523f855f1a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_d61b369c-af61-445c-958a-2f523f855f1a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_d61b369c-af61-445c-958a-2f523f855f1a" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_d61b369c-af61-445c-958a-2f523f855f1a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_10080e0d-e960-4947-97aa-42926a93b00e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_d61b369c-af61-445c-958a-2f523f855f1a" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_10080e0d-e960-4947-97aa-42926a93b00e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CrossCurrencyInterestRateContractMember_295f41d3-be51-49b4-8c62-671510f3761e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CrossCurrencyInterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_10080e0d-e960-4947-97aa-42926a93b00e" xlink:to="loc_us-gaap_CrossCurrencyInterestRateContractMember_295f41d3-be51-49b4-8c62-671510f3761e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_7cce14cd-88ad-4e96-98c6-e4f422114053" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByMeasurementFrequencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_e2d9c1bf-3bba-4afb-9c85-3dbc4e9f3dc3" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_7cce14cd-88ad-4e96-98c6-e4f422114053" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_7cce14cd-88ad-4e96-98c6-e4f422114053_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_7cce14cd-88ad-4e96-98c6-e4f422114053" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_7cce14cd-88ad-4e96-98c6-e4f422114053_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_ee089a13-a7dd-4c00-a566-6685874a2ebd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementFrequencyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_7cce14cd-88ad-4e96-98c6-e4f422114053" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_ee089a13-a7dd-4c00-a566-6685874a2ebd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_866d62e5-b15a-495e-8103-5b345680b85d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_ee089a13-a7dd-4c00-a566-6685874a2ebd" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_866d62e5-b15a-495e-8103-5b345680b85d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_72679046-829c-4bc8-b96b-f96d9592a1a4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_e2d9c1bf-3bba-4afb-9c85-3dbc4e9f3dc3" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_72679046-829c-4bc8-b96b-f96d9592a1a4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_72679046-829c-4bc8-b96b-f96d9592a1a4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_72679046-829c-4bc8-b96b-f96d9592a1a4" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_72679046-829c-4bc8-b96b-f96d9592a1a4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_b77c51c4-636a-4add-8e8b-94bfd44feb74" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_72679046-829c-4bc8-b96b-f96d9592a1a4" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_b77c51c4-636a-4add-8e8b-94bfd44feb74" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_8a5b5e1f-f454-4b59-858a-07516403fe69" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_b77c51c4-636a-4add-8e8b-94bfd44feb74" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_8a5b5e1f-f454-4b59-858a-07516403fe69" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_1087559d-bc82-4e0e-9483-61eb7371c40d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_b77c51c4-636a-4add-8e8b-94bfd44feb74" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_1087559d-bc82-4e0e-9483-61eb7371c40d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_89d74b07-fe64-458d-809a-6e55937c91f5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_b77c51c4-636a-4add-8e8b-94bfd44feb74" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_89d74b07-fe64-458d-809a-6e55937c91f5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsInHedgesAtFairValueNet_8e7afa3b-d98d-4857-9e30-6874d871e826" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentsInHedgesAtFairValueNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_09a89424-2a6f-44a5-9f9d-527bab6dda89" xlink:to="loc_us-gaap_DerivativeInstrumentsInHedgesAtFairValueNet_8e7afa3b-d98d-4857-9e30-6874d871e826" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDerivativesNotDesignatedAsHedgingInstrumentsAtFairValueNet_2d12719b-b55c-4155-beed-5b58055eb26c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherDerivativesNotDesignatedAsHedgingInstrumentsAtFairValueNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_09a89424-2a6f-44a5-9f9d-527bab6dda89" xlink:to="loc_us-gaap_OtherDerivativesNotDesignatedAsHedgingInstrumentsAtFairValueNet_2d12719b-b55c-4155-beed-5b58055eb26c" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/CommitmentsandContingenciesEnvironmentalDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#CommitmentsandContingenciesEnvironmentalDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/CommitmentsandContingenciesEnvironmentalDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_dac9a387-f847-4e83-a394-d1ffeef466f9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_9673e0f2-6b33-442c-9cb5-558a8bcb5594" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_dac9a387-f847-4e83-a394-d1ffeef466f9" xlink:to="loc_us-gaap_LossContingenciesTable_9673e0f2-6b33-442c-9cb5-558a8bcb5594" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_9139221a-b393-4965-96f7-070cb5835277" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_9673e0f2-6b33-442c-9cb5-558a8bcb5594" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_9139221a-b393-4965-96f7-070cb5835277" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_9139221a-b393-4965-96f7-070cb5835277_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_9139221a-b393-4965-96f7-070cb5835277" xlink:to="loc_us-gaap_LossContingencyNatureDomain_9139221a-b393-4965-96f7-070cb5835277_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_27fc5796-3390-47df-840b-3ee38f2fb6d9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_9139221a-b393-4965-96f7-070cb5835277" xlink:to="loc_us-gaap_LossContingencyNatureDomain_27fc5796-3390-47df-840b-3ee38f2fb6d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EnvironmentalIssueMember_b5dc4d69-8224-4974-a9fb-14a3c28f8f18" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EnvironmentalIssueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_27fc5796-3390-47df-840b-3ee38f2fb6d9" xlink:to="loc_us-gaap_EnvironmentalIssueMember_b5dc4d69-8224-4974-a9fb-14a3c28f8f18" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsGross_1b2a2c84-36a5-40bd-adf2-a4e9773c28a5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_dac9a387-f847-4e83-a394-d1ffeef466f9" xlink:to="loc_us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsGross_1b2a2c84-36a5-40bd-adf2-a4e9773c28a5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsGrossPeriodIncreaseDecrease_85a9f23e-90dd-4cc7-9451-e267c7b00c57" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsGrossPeriodIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_dac9a387-f847-4e83-a394-d1ffeef466f9" xlink:to="loc_us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsGrossPeriodIncreaseDecrease_85a9f23e-90dd-4cc7-9451-e267c7b00c57" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/CommitmentsandContingenciesAsbestosNarrativeDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#CommitmentsandContingenciesAsbestosNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/CommitmentsandContingenciesAsbestosNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_eb283478-5967-41f7-83c8-6d07a4482649" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_8be415f2-90b8-4a09-9940-7c599274ab0d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_eb283478-5967-41f7-83c8-6d07a4482649" xlink:to="loc_us-gaap_LossContingenciesTable_8be415f2-90b8-4a09-9940-7c599274ab0d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DamagesSoughtTypeAxis_01582956-e5b5-42b1-99f6-befa1fde640e" xlink:href="trs-20241231.xsd#trs_DamagesSoughtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_8be415f2-90b8-4a09-9940-7c599274ab0d" xlink:to="loc_trs_DamagesSoughtTypeAxis_01582956-e5b5-42b1-99f6-befa1fde640e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DamagesSoughtTypeDomain_01582956-e5b5-42b1-99f6-befa1fde640e_default" xlink:href="trs-20241231.xsd#trs_DamagesSoughtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_DamagesSoughtTypeAxis_01582956-e5b5-42b1-99f6-befa1fde640e" xlink:to="loc_trs_DamagesSoughtTypeDomain_01582956-e5b5-42b1-99f6-befa1fde640e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DamagesSoughtTypeDomain_2b109346-9390-4562-ba81-8d3b59dcec8d" xlink:href="trs-20241231.xsd#trs_DamagesSoughtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_DamagesSoughtTypeAxis_01582956-e5b5-42b1-99f6-befa1fde640e" xlink:to="loc_trs_DamagesSoughtTypeDomain_2b109346-9390-4562-ba81-8d3b59dcec8d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_PunitiveOnlyDamagesMember_ac46a69c-0f7b-4d35-a6be-7ca4f188d6bf" xlink:href="trs-20241231.xsd#trs_PunitiveOnlyDamagesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtTypeDomain_2b109346-9390-4562-ba81-8d3b59dcec8d" xlink:to="loc_trs_PunitiveOnlyDamagesMember_ac46a69c-0f7b-4d35-a6be-7ca4f188d6bf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_5d30f453-8e30-4fea-b982-ff904e572a42" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_8be415f2-90b8-4a09-9940-7c599274ab0d" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_5d30f453-8e30-4fea-b982-ff904e572a42" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_5d30f453-8e30-4fea-b982-ff904e572a42_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_5d30f453-8e30-4fea-b982-ff904e572a42" xlink:to="loc_us-gaap_LossContingencyNatureDomain_5d30f453-8e30-4fea-b982-ff904e572a42_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_e99380e4-8a73-4c75-ba16-bb0f13d7f8d3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_5d30f453-8e30-4fea-b982-ff904e572a42" xlink:to="loc_us-gaap_LossContingencyNatureDomain_e99380e4-8a73-4c75-ba16-bb0f13d7f8d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AsbestosIssueMember_0720b217-9149-4b82-933e-a9bfa482613a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AsbestosIssueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_e99380e4-8a73-4c75-ba16-bb0f13d7f8d3" xlink:to="loc_us-gaap_AsbestosIssueMember_0720b217-9149-4b82-933e-a9bfa482613a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EnvironmentalIssueMember_108537d0-4bfe-45d7-a7b4-80260358fc35" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EnvironmentalIssueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_e99380e4-8a73-4c75-ba16-bb0f13d7f8d3" xlink:to="loc_us-gaap_EnvironmentalIssueMember_108537d0-4bfe-45d7-a7b4-80260358fc35" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusAxis_53a0f7d0-63a8-4c02-a5c1-ecc5a6c9efbb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LitigationStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_8be415f2-90b8-4a09-9940-7c599274ab0d" xlink:to="loc_us-gaap_LitigationStatusAxis_53a0f7d0-63a8-4c02-a5c1-ecc5a6c9efbb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_53a0f7d0-63a8-4c02-a5c1-ecc5a6c9efbb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LitigationStatusAxis_53a0f7d0-63a8-4c02-a5c1-ecc5a6c9efbb" xlink:to="loc_us-gaap_LitigationStatusDomain_53a0f7d0-63a8-4c02-a5c1-ecc5a6c9efbb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_c23e9caf-9ab6-4be3-8b8d-640fe46c8e07" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LitigationStatusAxis_53a0f7d0-63a8-4c02-a5c1-ecc5a6c9efbb" xlink:to="loc_us-gaap_LitigationStatusDomain_c23e9caf-9ab6-4be3-8b8d-640fe46c8e07" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PendingLitigationMember_7571f586-111c-4448-941d-5d3a80c75b55" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PendingLitigationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LitigationStatusDomain_c23e9caf-9ab6-4be3-8b8d-640fe46c8e07" xlink:to="loc_us-gaap_PendingLitigationMember_7571f586-111c-4448-941d-5d3a80c75b55" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_cfe0e8c8-e98f-4157-ba22-2474c19645a8" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_8be415f2-90b8-4a09-9940-7c599274ab0d" xlink:to="loc_srt_RangeAxis_cfe0e8c8-e98f-4157-ba22-2474c19645a8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_cfe0e8c8-e98f-4157-ba22-2474c19645a8_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_cfe0e8c8-e98f-4157-ba22-2474c19645a8" xlink:to="loc_srt_RangeMember_cfe0e8c8-e98f-4157-ba22-2474c19645a8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_caa0f1ee-8b71-48d2-bbd8-9c091ed11b01" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_cfe0e8c8-e98f-4157-ba22-2474c19645a8" xlink:to="loc_srt_RangeMember_caa0f1ee-8b71-48d2-bbd8-9c091ed11b01" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_baacbdf5-4946-426b-9170-9ee61996efcb" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_caa0f1ee-8b71-48d2-bbd8-9c091ed11b01" xlink:to="loc_srt_MinimumMember_baacbdf5-4946-426b-9170-9ee61996efcb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_2bf67161-6439-4db6-81d3-78a2a6d92450" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_caa0f1ee-8b71-48d2-bbd8-9c091ed11b01" xlink:to="loc_srt_MaximumMember_2bf67161-6439-4db6-81d3-78a2a6d92450" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_c9be15b3-de10-4b12-888b-e5cb0198d158" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_8be415f2-90b8-4a09-9940-7c599274ab0d" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_c9be15b3-de10-4b12-888b-e5cb0198d158" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_c9be15b3-de10-4b12-888b-e5cb0198d158_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_c9be15b3-de10-4b12-888b-e5cb0198d158" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_c9be15b3-de10-4b12-888b-e5cb0198d158_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_72c45df0-4bd6-4014-be8f-cbc053ae48c7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_c9be15b3-de10-4b12-888b-e5cb0198d158" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_72c45df0-4bd6-4014-be8f-cbc053ae48c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_40f6bbaf-8406-424c-8940-c127b18e37cd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_72c45df0-4bd6-4014-be8f-cbc053ae48c7" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_40f6bbaf-8406-424c-8940-c127b18e37cd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyDamagesSoughtValue_917603a1-fc34-4c3d-8da5-11c27a29b88e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyDamagesSoughtValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_eb283478-5967-41f7-83c8-6d07a4482649" xlink:to="loc_us-gaap_LossContingencyDamagesSoughtValue_917603a1-fc34-4c3d-8da5-11c27a29b88e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_LossContingencyPendingCasesNumber_c3e052dc-c519-414a-af7f-8e993a49ca43" xlink:href="trs-20241231.xsd#trs_LossContingencyPendingCasesNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_eb283478-5967-41f7-83c8-6d07a4482649" xlink:to="loc_trs_LossContingencyPendingCasesNumber_c3e052dc-c519-414a-af7f-8e993a49ca43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber_e48340c8-d25e-4dc6-a2da-246a431fc555" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyPendingClaimsNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_eb283478-5967-41f7-83c8-6d07a4482649" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_e48340c8-d25e-4dc6-a2da-246a431fc555" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_LossContingencyNumberofPlaintiffsSpecifyingDamagesSought_957ec01f-41a3-411c-ab27-0e66f4a28594" xlink:href="trs-20241231.xsd#trs_LossContingencyNumberofPlaintiffsSpecifyingDamagesSought"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_eb283478-5967-41f7-83c8-6d07a4482649" xlink:to="loc_trs_LossContingencyNumberofPlaintiffsSpecifyingDamagesSought_957ec01f-41a3-411c-ab27-0e66f4a28594" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementExpense_d715857c-5344-4371-b7c2-8eda59fef2b5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LitigationSettlementExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_eb283478-5967-41f7-83c8-6d07a4482649" xlink:to="loc_us-gaap_LitigationSettlementExpense_d715857c-5344-4371-b7c2-8eda59fef2b5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_PercentageOfSettlementAndDefenseCostsCoveredByInsurance_03d69d74-86f1-4d11-8c0c-4ed2cb2c80c4" xlink:href="trs-20241231.xsd#trs_PercentageOfSettlementAndDefenseCostsCoveredByInsurance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_eb283478-5967-41f7-83c8-6d07a4482649" xlink:to="loc_trs_PercentageOfSettlementAndDefenseCostsCoveredByInsurance_03d69d74-86f1-4d11-8c0c-4ed2cb2c80c4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesSubjectToCompromiseAsbestosObligations_86726776-bb4f-4432-b6c4-07817a00c489" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesSubjectToCompromiseAsbestosObligations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_eb283478-5967-41f7-83c8-6d07a4482649" xlink:to="loc_us-gaap_LiabilitiesSubjectToCompromiseAsbestosObligations_86726776-bb4f-4432-b6c4-07817a00c489" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ImpactOfChangeInAccountingPrinciple_104bd07e-4045-48cf-8aa7-bc066206ced2" xlink:href="trs-20241231.xsd#trs_ImpactOfChangeInAccountingPrinciple"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_eb283478-5967-41f7-83c8-6d07a4482649" xlink:to="loc_trs_ImpactOfChangeInAccountingPrinciple_104bd07e-4045-48cf-8aa7-bc066206ced2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsGrossPeriodIncreaseDecrease_f2659a3f-8ff6-4b3c-bf05-966a881e7b20" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsGrossPeriodIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_eb283478-5967-41f7-83c8-6d07a4482649" xlink:to="loc_us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsGrossPeriodIncreaseDecrease_f2659a3f-8ff6-4b3c-bf05-966a881e7b20" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/CommitmentsandContingenciesAsbestosClaimantandSettlementDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#CommitmentsandContingenciesAsbestosClaimantandSettlementDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/CommitmentsandContingenciesAsbestosClaimantandSettlementDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_458f0afb-6657-4f33-ad48-15d029d3602d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_52db49cc-1856-4765-9c3c-6146ab221d37" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_458f0afb-6657-4f33-ad48-15d029d3602d" xlink:to="loc_us-gaap_LossContingenciesTable_52db49cc-1856-4765-9c3c-6146ab221d37" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_286a564a-54ba-48a5-a977-6edfa9d5e299" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_52db49cc-1856-4765-9c3c-6146ab221d37" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_286a564a-54ba-48a5-a977-6edfa9d5e299" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_286a564a-54ba-48a5-a977-6edfa9d5e299_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_286a564a-54ba-48a5-a977-6edfa9d5e299" xlink:to="loc_us-gaap_LossContingencyNatureDomain_286a564a-54ba-48a5-a977-6edfa9d5e299_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_1c9d784b-8e6a-4413-9e5b-ef9cb3724a63" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_286a564a-54ba-48a5-a977-6edfa9d5e299" xlink:to="loc_us-gaap_LossContingencyNatureDomain_1c9d784b-8e6a-4413-9e5b-ef9cb3724a63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AsbestosIssueMember_72ace829-09cc-4425-89ad-7faa65fcdb2b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AsbestosIssueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_1c9d784b-8e6a-4413-9e5b-ef9cb3724a63" xlink:to="loc_us-gaap_AsbestosIssueMember_72ace829-09cc-4425-89ad-7faa65fcdb2b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_f685830e-ff4c-4db9-aaee-5df0b5656185" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_52db49cc-1856-4765-9c3c-6146ab221d37" xlink:to="loc_srt_RangeAxis_f685830e-ff4c-4db9-aaee-5df0b5656185" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_f685830e-ff4c-4db9-aaee-5df0b5656185_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_f685830e-ff4c-4db9-aaee-5df0b5656185" xlink:to="loc_srt_RangeMember_f685830e-ff4c-4db9-aaee-5df0b5656185_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_0297f4e1-d358-4244-8e5d-4b9049b96c57" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_f685830e-ff4c-4db9-aaee-5df0b5656185" xlink:to="loc_srt_RangeMember_0297f4e1-d358-4244-8e5d-4b9049b96c57" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_7c8d9f21-aaae-4cb4-a4f6-5bd9f3b514e0" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_0297f4e1-d358-4244-8e5d-4b9049b96c57" xlink:to="loc_srt_MinimumMember_7c8d9f21-aaae-4cb4-a4f6-5bd9f3b514e0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_7f459ce8-a859-4e14-8d44-6852c58521de" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_0297f4e1-d358-4244-8e5d-4b9049b96c57" xlink:to="loc_srt_MaximumMember_7f459ce8-a859-4e14-8d44-6852c58521de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNewClaimsFiledNumber_6867f5fd-1ec7-4854-872f-40231ad7b8a2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNewClaimsFiledNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_458f0afb-6657-4f33-ad48-15d029d3602d" xlink:to="loc_us-gaap_LossContingencyNewClaimsFiledNumber_6867f5fd-1ec7-4854-872f-40231ad7b8a2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyClaimsDismissedNumber_b5314f48-23b2-42f5-9a39-effc5a89686b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyClaimsDismissedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_458f0afb-6657-4f33-ad48-15d029d3602d" xlink:to="loc_us-gaap_LossContingencyClaimsDismissedNumber_b5314f48-23b2-42f5-9a39-effc5a89686b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyClaimsSettledNumber_0250cdc5-d0d6-434f-98a7-ae6918c3bb25" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyClaimsSettledNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_458f0afb-6657-4f33-ad48-15d029d3602d" xlink:to="loc_us-gaap_LossContingencyClaimsSettledNumber_0250cdc5-d0d6-434f-98a7-ae6918c3bb25" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber_607f43d9-e21c-4a1f-980f-d69594ae1c4a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyPendingClaimsNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_458f0afb-6657-4f33-ad48-15d029d3602d" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_607f43d9-e21c-4a1f-980f-d69594ae1c4a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_LossContingencySettlementAgreementAverageConsideration_de3071d1-8940-4706-b1ad-ee3d3058a319" xlink:href="trs-20241231.xsd#trs_LossContingencySettlementAgreementAverageConsideration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_458f0afb-6657-4f33-ad48-15d029d3602d" xlink:to="loc_trs_LossContingencySettlementAgreementAverageConsideration_de3071d1-8940-4706-b1ad-ee3d3058a319" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LegalFees_a40504ec-a9e1-491f-8d48-9a3fd3549ac3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LegalFees"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_458f0afb-6657-4f33-ad48-15d029d3602d" xlink:to="loc_us-gaap_LegalFees_a40504ec-a9e1-491f-8d48-9a3fd3549ac3" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/CommitmentsandContingenciesAsbestosDamagesSoughtDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#CommitmentsandContingenciesAsbestosDamagesSoughtDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/CommitmentsandContingenciesAsbestosDamagesSoughtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_5d292919-5099-458d-a373-bb9e0c61035d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_37f1c33a-06e7-40f6-a8f1-d1b6ef12fe80" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_5d292919-5099-458d-a373-bb9e0c61035d" xlink:to="loc_us-gaap_LossContingenciesTable_37f1c33a-06e7-40f6-a8f1-d1b6ef12fe80" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_51eb923c-be13-4539-9b85-6eba8e0dcfe1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_37f1c33a-06e7-40f6-a8f1-d1b6ef12fe80" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_51eb923c-be13-4539-9b85-6eba8e0dcfe1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_51eb923c-be13-4539-9b85-6eba8e0dcfe1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_51eb923c-be13-4539-9b85-6eba8e0dcfe1" xlink:to="loc_us-gaap_LossContingencyNatureDomain_51eb923c-be13-4539-9b85-6eba8e0dcfe1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_4157f467-d50a-4b17-9e22-16eb86639df7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_51eb923c-be13-4539-9b85-6eba8e0dcfe1" xlink:to="loc_us-gaap_LossContingencyNatureDomain_4157f467-d50a-4b17-9e22-16eb86639df7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AsbestosIssueMember_b49411d1-3117-4d53-9439-143c08e2ed26" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AsbestosIssueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_4157f467-d50a-4b17-9e22-16eb86639df7" xlink:to="loc_us-gaap_AsbestosIssueMember_b49411d1-3117-4d53-9439-143c08e2ed26" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusAxis_5789ef09-eaac-4889-b5b7-57a16444117f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LitigationStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_37f1c33a-06e7-40f6-a8f1-d1b6ef12fe80" xlink:to="loc_us-gaap_LitigationStatusAxis_5789ef09-eaac-4889-b5b7-57a16444117f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_5789ef09-eaac-4889-b5b7-57a16444117f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LitigationStatusAxis_5789ef09-eaac-4889-b5b7-57a16444117f" xlink:to="loc_us-gaap_LitigationStatusDomain_5789ef09-eaac-4889-b5b7-57a16444117f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_0ff75c37-35d6-4ddb-8439-3c444493bb34" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LitigationStatusAxis_5789ef09-eaac-4889-b5b7-57a16444117f" xlink:to="loc_us-gaap_LitigationStatusDomain_0ff75c37-35d6-4ddb-8439-3c444493bb34" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PendingLitigationMember_3f601d4f-f2e0-4eda-9a88-49b359800f60" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PendingLitigationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LitigationStatusDomain_0ff75c37-35d6-4ddb-8439-3c444493bb34" xlink:to="loc_us-gaap_PendingLitigationMember_3f601d4f-f2e0-4eda-9a88-49b359800f60" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DamagesSoughtTypeAxis_bd2a4f11-91f7-4c14-80f7-6a6335a76ce4" xlink:href="trs-20241231.xsd#trs_DamagesSoughtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_37f1c33a-06e7-40f6-a8f1-d1b6ef12fe80" xlink:to="loc_trs_DamagesSoughtTypeAxis_bd2a4f11-91f7-4c14-80f7-6a6335a76ce4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DamagesSoughtTypeDomain_bd2a4f11-91f7-4c14-80f7-6a6335a76ce4_default" xlink:href="trs-20241231.xsd#trs_DamagesSoughtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_DamagesSoughtTypeAxis_bd2a4f11-91f7-4c14-80f7-6a6335a76ce4" xlink:to="loc_trs_DamagesSoughtTypeDomain_bd2a4f11-91f7-4c14-80f7-6a6335a76ce4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DamagesSoughtTypeDomain_5c9777bb-fe55-40e4-848c-008a79f28160" xlink:href="trs-20241231.xsd#trs_DamagesSoughtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_DamagesSoughtTypeAxis_bd2a4f11-91f7-4c14-80f7-6a6335a76ce4" xlink:to="loc_trs_DamagesSoughtTypeDomain_5c9777bb-fe55-40e4-848c-008a79f28160" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_CompensatoryAndPunitiveDamagesMember_394540f7-79e9-4f92-924e-37461e2300ef" xlink:href="trs-20241231.xsd#trs_CompensatoryAndPunitiveDamagesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtTypeDomain_5c9777bb-fe55-40e4-848c-008a79f28160" xlink:to="loc_trs_CompensatoryAndPunitiveDamagesMember_394540f7-79e9-4f92-924e-37461e2300ef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_CompensatoryOnlyDamagesMember_524d17d7-5834-4466-bea1-300447eb7839" xlink:href="trs-20241231.xsd#trs_CompensatoryOnlyDamagesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtTypeDomain_5c9777bb-fe55-40e4-848c-008a79f28160" xlink:to="loc_trs_CompensatoryOnlyDamagesMember_524d17d7-5834-4466-bea1-300447eb7839" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_PunitiveOnlyDamagesMember_864afee5-bcbb-4d7a-9853-ed203cf44aa5" xlink:href="trs-20241231.xsd#trs_PunitiveOnlyDamagesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtTypeDomain_5c9777bb-fe55-40e4-848c-008a79f28160" xlink:to="loc_trs_PunitiveOnlyDamagesMember_864afee5-bcbb-4d7a-9853-ed203cf44aa5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DamagesSoughtRangeAxis_98c20b36-dc07-460d-aee7-2a1971a81c90" xlink:href="trs-20241231.xsd#trs_DamagesSoughtRangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_37f1c33a-06e7-40f6-a8f1-d1b6ef12fe80" xlink:to="loc_trs_DamagesSoughtRangeAxis_98c20b36-dc07-460d-aee7-2a1971a81c90" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DamagesSoughtDomain_98c20b36-dc07-460d-aee7-2a1971a81c90_default" xlink:href="trs-20241231.xsd#trs_DamagesSoughtDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_DamagesSoughtRangeAxis_98c20b36-dc07-460d-aee7-2a1971a81c90" xlink:to="loc_trs_DamagesSoughtDomain_98c20b36-dc07-460d-aee7-2a1971a81c90_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DamagesSoughtDomain_839c3378-d96a-430c-a354-d244fc662a0c" xlink:href="trs-20241231.xsd#trs_DamagesSoughtDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_DamagesSoughtRangeAxis_98c20b36-dc07-460d-aee7-2a1971a81c90" xlink:to="loc_trs_DamagesSoughtDomain_839c3378-d96a-430c-a354-d244fc662a0c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Range1Member_79b7916c-6a40-4e3e-8774-d883fe04cbb3" xlink:href="trs-20241231.xsd#trs_Range1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtDomain_839c3378-d96a-430c-a354-d244fc662a0c" xlink:to="loc_trs_Range1Member_79b7916c-6a40-4e3e-8774-d883fe04cbb3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Range2Member_8cd4d0ba-edc3-4495-9e0a-2aa0dfd4354e" xlink:href="trs-20241231.xsd#trs_Range2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtDomain_839c3378-d96a-430c-a354-d244fc662a0c" xlink:to="loc_trs_Range2Member_8cd4d0ba-edc3-4495-9e0a-2aa0dfd4354e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Range3Member_7e0557f9-3fba-4ec5-ad77-b12b0706eced" xlink:href="trs-20241231.xsd#trs_Range3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtDomain_839c3378-d96a-430c-a354-d244fc662a0c" xlink:to="loc_trs_Range3Member_7e0557f9-3fba-4ec5-ad77-b12b0706eced" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_dbd87206-9b88-457f-9f1d-14c715938e6d" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_37f1c33a-06e7-40f6-a8f1-d1b6ef12fe80" xlink:to="loc_srt_RangeAxis_dbd87206-9b88-457f-9f1d-14c715938e6d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_dbd87206-9b88-457f-9f1d-14c715938e6d_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_dbd87206-9b88-457f-9f1d-14c715938e6d" xlink:to="loc_srt_RangeMember_dbd87206-9b88-457f-9f1d-14c715938e6d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_da30db51-95ac-4e34-97cf-d1785669b1e1" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_dbd87206-9b88-457f-9f1d-14c715938e6d" xlink:to="loc_srt_RangeMember_da30db51-95ac-4e34-97cf-d1785669b1e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_b170ecb3-f7e6-420c-9d72-d076c7a1a2f6" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_da30db51-95ac-4e34-97cf-d1785669b1e1" xlink:to="loc_srt_MinimumMember_b170ecb3-f7e6-420c-9d72-d076c7a1a2f6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_54600e66-69e3-4b74-acca-153593eeba1a" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_da30db51-95ac-4e34-97cf-d1785669b1e1" xlink:to="loc_srt_MaximumMember_54600e66-69e3-4b74-acca-153593eeba1a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyDamagesSoughtValue_7c3f8afa-ef59-46b7-b89c-d6a390dd3598" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyDamagesSoughtValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_5d292919-5099-458d-a373-bb9e0c61035d" xlink:to="loc_us-gaap_LossContingencyDamagesSoughtValue_7c3f8afa-ef59-46b7-b89c-d6a390dd3598" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_LossContingencyNumberofPlaintiffsSpecifyingDamagesSought_6f3209d8-d588-474a-9a67-29f63a9abf97" xlink:href="trs-20241231.xsd#trs_LossContingencyNumberofPlaintiffsSpecifyingDamagesSought"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_5d292919-5099-458d-a373-bb9e0c61035d" xlink:to="loc_trs_LossContingencyNumberofPlaintiffsSpecifyingDamagesSought_6f3209d8-d588-474a-9a67-29f63a9abf97" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/CommitmentsandContingenciesMetaldyneCorporationDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#CommitmentsandContingenciesMetaldyneCorporationDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/CommitmentsandContingenciesMetaldyneCorporationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_93c17707-27d3-46d8-b396-dd8c55a6889b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_4dd3670f-c1f0-416c-91cc-a452b7a0b9c0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_93c17707-27d3-46d8-b396-dd8c55a6889b" xlink:to="loc_us-gaap_LossContingenciesTable_4dd3670f-c1f0-416c-91cc-a452b7a0b9c0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_2351417e-7637-4b98-ad98-94bc5ffdb606" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_4dd3670f-c1f0-416c-91cc-a452b7a0b9c0" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_2351417e-7637-4b98-ad98-94bc5ffdb606" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_2351417e-7637-4b98-ad98-94bc5ffdb606_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_2351417e-7637-4b98-ad98-94bc5ffdb606" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_2351417e-7637-4b98-ad98-94bc5ffdb606_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_1731f70e-a2db-44b7-98ce-0842b3aefdc2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_2351417e-7637-4b98-ad98-94bc5ffdb606" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_1731f70e-a2db-44b7-98ce-0842b3aefdc2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_baaf6f30-5039-44b7-a645-dbf93dfdf1ba" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_1731f70e-a2db-44b7-98ce-0842b3aefdc2" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_baaf6f30-5039-44b7-a645-dbf93dfdf1ba" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualCarryingValuePeriodIncreaseDecrease_04b12541-4a74-4fbb-89fa-374eec8b843d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyAccrualCarryingValuePeriodIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_93c17707-27d3-46d8-b396-dd8c55a6889b" xlink:to="loc_us-gaap_LossContingencyAccrualCarryingValuePeriodIncreaseDecrease_04b12541-4a74-4fbb-89fa-374eec8b843d" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/CommitmentsandContingenciesClaimsandLitigationDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#CommitmentsandContingenciesClaimsandLitigationDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/CommitmentsandContingenciesClaimsandLitigationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_7dfd0407-a840-4561-9df4-a1023090f3a7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_4c6bf027-e23e-4c92-a13b-c48dc50c615e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_7dfd0407-a840-4561-9df4-a1023090f3a7" xlink:to="loc_us-gaap_LossContingenciesTable_4c6bf027-e23e-4c92-a13b-c48dc50c615e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_9ea5ad29-6767-4afe-abf5-de96f8a4214b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_4c6bf027-e23e-4c92-a13b-c48dc50c615e" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_9ea5ad29-6767-4afe-abf5-de96f8a4214b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_9ea5ad29-6767-4afe-abf5-de96f8a4214b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_9ea5ad29-6767-4afe-abf5-de96f8a4214b" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_9ea5ad29-6767-4afe-abf5-de96f8a4214b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_88284658-7dba-4f2f-9ae9-9a9b2f61cae6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_9ea5ad29-6767-4afe-abf5-de96f8a4214b" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_88284658-7dba-4f2f-9ae9-9a9b2f61cae6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_3c366b1c-9487-48db-a545-96abed902394" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_4c6bf027-e23e-4c92-a13b-c48dc50c615e" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_3c366b1c-9487-48db-a545-96abed902394" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_3c366b1c-9487-48db-a545-96abed902394_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_3c366b1c-9487-48db-a545-96abed902394" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_3c366b1c-9487-48db-a545-96abed902394_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_73eff1a1-9413-46ae-9524-3dbc1cf04974" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_3c366b1c-9487-48db-a545-96abed902394" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_73eff1a1-9413-46ae-9524-3dbc1cf04974" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusAxis_db062d4e-a4b5-4d2c-860a-8972aba16fa2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LitigationStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_4c6bf027-e23e-4c92-a13b-c48dc50c615e" xlink:to="loc_us-gaap_LitigationStatusAxis_db062d4e-a4b5-4d2c-860a-8972aba16fa2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_db062d4e-a4b5-4d2c-860a-8972aba16fa2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LitigationStatusAxis_db062d4e-a4b5-4d2c-860a-8972aba16fa2" xlink:to="loc_us-gaap_LitigationStatusDomain_db062d4e-a4b5-4d2c-860a-8972aba16fa2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_db152837-f569-4655-ab6a-ff052e66e222" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LitigationStatusAxis_db062d4e-a4b5-4d2c-860a-8972aba16fa2" xlink:to="loc_us-gaap_LitigationStatusDomain_db152837-f569-4655-ab6a-ff052e66e222" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_c497334f-7d29-45d3-8fb5-7a291ab215a5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_4c6bf027-e23e-4c92-a13b-c48dc50c615e" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_c497334f-7d29-45d3-8fb5-7a291ab215a5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_c497334f-7d29-45d3-8fb5-7a291ab215a5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_c497334f-7d29-45d3-8fb5-7a291ab215a5" xlink:to="loc_us-gaap_LossContingencyNatureDomain_c497334f-7d29-45d3-8fb5-7a291ab215a5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_6d9c4775-ccdf-4fa3-b3c9-d2ae8950bd6c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_c497334f-7d29-45d3-8fb5-7a291ab215a5" xlink:to="loc_us-gaap_LossContingencyNatureDomain_6d9c4775-ccdf-4fa3-b3c9-d2ae8950bd6c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_OrdinaryCourseClaimsMember_340114f4-1f79-4633-bd45-5fabdc658bc1" xlink:href="trs-20241231.xsd#trs_OrdinaryCourseClaimsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_6d9c4775-ccdf-4fa3-b3c9-d2ae8950bd6c" xlink:to="loc_trs_OrdinaryCourseClaimsMember_340114f4-1f79-4633-bd45-5fabdc658bc1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyDamagesSoughtValue_3bf7a4b3-2084-456a-89e4-eeb880b85e02" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyDamagesSoughtValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_7dfd0407-a840-4561-9df4-a1023090f3a7" xlink:to="loc_us-gaap_LossContingencyDamagesSoughtValue_3bf7a4b3-2084-456a-89e4-eeb880b85e02" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyDamagesPaidValue_0af05b07-5444-467f-b884-ebe86e41ec7f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyDamagesPaidValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_7dfd0407-a840-4561-9df4-a1023090f3a7" xlink:to="loc_us-gaap_LossContingencyDamagesPaidValue_0af05b07-5444-467f-b884-ebe86e41ec7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyEstimatedRecoveryFromThirdParty_4be0dada-d8d9-4c3e-955d-5c06ecdd1048" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyEstimatedRecoveryFromThirdParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_7dfd0407-a840-4561-9df4-a1023090f3a7" xlink:to="loc_us-gaap_LossContingencyEstimatedRecoveryFromThirdParty_4be0dada-d8d9-4c3e-955d-5c06ecdd1048" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EmployeeBenefitPlansDefinedBenefitPlanNarrativeDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EmployeeBenefitPlansDefinedBenefitPlanNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EmployeeBenefitPlansDefinedBenefitPlanNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_d69f0602-36ad-4a31-8803-97e37b3d9036" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_fd1b019e-a747-4626-93f5-14f41cfccb5b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_d69f0602-36ad-4a31-8803-97e37b3d9036" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_fd1b019e-a747-4626-93f5-14f41cfccb5b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_8e3bfccd-ddb8-4f31-aa95-51a9a9567c89" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_fd1b019e-a747-4626-93f5-14f41cfccb5b" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_8e3bfccd-ddb8-4f31-aa95-51a9a9567c89" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_8e3bfccd-ddb8-4f31-aa95-51a9a9567c89_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_8e3bfccd-ddb8-4f31-aa95-51a9a9567c89" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_8e3bfccd-ddb8-4f31-aa95-51a9a9567c89_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_5a85d00f-3f75-4ec9-a8b8-b2f341b66405" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_8e3bfccd-ddb8-4f31-aa95-51a9a9567c89" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_5a85d00f-3f75-4ec9-a8b8-b2f341b66405" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_422d008d-6a13-4e3c-a3dc-256995164778" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_5a85d00f-3f75-4ec9-a8b8-b2f341b66405" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_422d008d-6a13-4e3c-a3dc-256995164778" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_d7ab3475-2073-41e2-8ea0-d16e371d19a0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_fd1b019e-a747-4626-93f5-14f41cfccb5b" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_d7ab3475-2073-41e2-8ea0-d16e371d19a0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_d7ab3475-2073-41e2-8ea0-d16e371d19a0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_d7ab3475-2073-41e2-8ea0-d16e371d19a0" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_d7ab3475-2073-41e2-8ea0-d16e371d19a0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_e4b97145-6db4-418c-ad1d-d3bbd4b89940" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_d7ab3475-2073-41e2-8ea0-d16e371d19a0" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_e4b97145-6db4-418c-ad1d-d3bbd4b89940" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_063664f5-0638-4da7-b1fd-448d684262ab" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_fd1b019e-a747-4626-93f5-14f41cfccb5b" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_063664f5-0638-4da7-b1fd-448d684262ab" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_063664f5-0638-4da7-b1fd-448d684262ab_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_063664f5-0638-4da7-b1fd-448d684262ab" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_063664f5-0638-4da7-b1fd-448d684262ab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8b50b372-9500-4796-9cb2-de6a35b2ad44" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_063664f5-0638-4da7-b1fd-448d684262ab" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_8b50b372-9500-4796-9cb2-de6a35b2ad44" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract_f8763391-0f7b-4a06-833f-9689e5d0a39c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_d69f0602-36ad-4a31-8803-97e37b3d9036" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract_f8763391-0f7b-4a06-833f-9689e5d0a39c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear_6374f5c4-c2d6-4381-87f0-9c3525257d70" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearAbstract_f8763391-0f7b-4a06-833f-9689e5d0a39c" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear_6374f5c4-c2d6-4381-87f0-9c3525257d70" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanEstimatedFutureEmployerContributionsAbstract_e0da1b72-d5b0-4ce8-83a2-573263cdbdd2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanEstimatedFutureEmployerContributionsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_d69f0602-36ad-4a31-8803-97e37b3d9036" xlink:to="loc_us-gaap_DefinedBenefitPlanEstimatedFutureEmployerContributionsAbstract_e0da1b72-d5b0-4ce8-83a2-573263cdbdd2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_ba535aed-2e00-4c05-8426-5ab184d6a63f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanEstimatedFutureEmployerContributionsAbstract_e0da1b72-d5b0-4ce8-83a2-573263cdbdd2" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_ba535aed-2e00-4c05-8426-5ab184d6a63f" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EmployeeBenefitPlansNetPeriodicPensionandPostretirementBenefitCostsDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EmployeeBenefitPlansNetPeriodicPensionandPostretirementBenefitCostsDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EmployeeBenefitPlansNetPeriodicPensionandPostretirementBenefitCostsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_09447afb-6e2c-4ece-9f25-32fc0337f0e7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_11211482-5425-4ebc-9348-08fdcb7c800a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_09447afb-6e2c-4ece-9f25-32fc0337f0e7" xlink:to="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_11211482-5425-4ebc-9348-08fdcb7c800a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_a0e32bf6-ac73-42ae-9629-88a2e8eaf339" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_11211482-5425-4ebc-9348-08fdcb7c800a" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_a0e32bf6-ac73-42ae-9629-88a2e8eaf339" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_a0e32bf6-ac73-42ae-9629-88a2e8eaf339_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_a0e32bf6-ac73-42ae-9629-88a2e8eaf339" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_a0e32bf6-ac73-42ae-9629-88a2e8eaf339_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_d565ed28-b0bf-4bf9-a6d6-85657658976a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_a0e32bf6-ac73-42ae-9629-88a2e8eaf339" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_d565ed28-b0bf-4bf9-a6d6-85657658976a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_e5423a68-bed8-49a7-9147-0a7d50f64210" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_d565ed28-b0bf-4bf9-a6d6-85657658976a" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_e5423a68-bed8-49a7-9147-0a7d50f64210" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_07083dd8-bcd1-4e51-a463-cc08d3c3bdbc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_11211482-5425-4ebc-9348-08fdcb7c800a" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_07083dd8-bcd1-4e51-a463-cc08d3c3bdbc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_07083dd8-bcd1-4e51-a463-cc08d3c3bdbc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_07083dd8-bcd1-4e51-a463-cc08d3c3bdbc" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_07083dd8-bcd1-4e51-a463-cc08d3c3bdbc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_fb531f14-7aa4-4da5-b27e-b2f7e105037e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_07083dd8-bcd1-4e51-a463-cc08d3c3bdbc" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_fb531f14-7aa4-4da5-b27e-b2f7e105037e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_f58eac06-11af-4e83-b6f4-6b7f05fc7381" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_fb531f14-7aa4-4da5-b27e-b2f7e105037e" xlink:to="loc_us-gaap_ForeignPlanMember_f58eac06-11af-4e83-b6f4-6b7f05fc7381" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_adf69de1-d584-41ca-b1ac-197402a3f778" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_fb531f14-7aa4-4da5-b27e-b2f7e105037e" xlink:to="loc_us-gaap_DomesticPlanMember_adf69de1-d584-41ca-b1ac-197402a3f778" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_a4fe9d85-dbe6-41fe-aa62-a548420866ca" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_adf69de1-d584-41ca-b1ac-197402a3f778" xlink:to="loc_country_US_a4fe9d85-dbe6-41fe-aa62-a548420866ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_e7c83a9b-b080-4999-9be1-69c52acdaee5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_09447afb-6e2c-4ece-9f25-32fc0337f0e7" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_e7c83a9b-b080-4999-9be1-69c52acdaee5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditInterestCostStatementOfIncomeOrComprehensiveIncomeExtensibleList_3476fc3c-d62a-4b98-a894-6217d07c337a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditInterestCostStatementOfIncomeOrComprehensiveIncomeExtensibleList"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_09447afb-6e2c-4ece-9f25-32fc0337f0e7" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditInterestCostStatementOfIncomeOrComprehensiveIncomeExtensibleList_3476fc3c-d62a-4b98-a894-6217d07c337a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_969cf09f-58d7-46eb-8512-26229fd6c39f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_09447afb-6e2c-4ece-9f25-32fc0337f0e7" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_969cf09f-58d7-46eb-8512-26229fd6c39f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditExpectedReturnLossStatementOfIncomeOrComprehensiveIncomeExtensibleList_99106025-1b4d-4287-834b-295044a47d2e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditExpectedReturnLossStatementOfIncomeOrComprehensiveIncomeExtensibleList"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_09447afb-6e2c-4ece-9f25-32fc0337f0e7" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditExpectedReturnLossStatementOfIncomeOrComprehensiveIncomeExtensibleList_99106025-1b4d-4287-834b-295044a47d2e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_a2c5b6db-255c-4290-a0ad-17195eccdd2d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_09447afb-6e2c-4ece-9f25-32fc0337f0e7" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_a2c5b6db-255c-4290-a0ad-17195eccdd2d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_76001842-8d43-4620-869a-4f8ac0c5fc10" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_09447afb-6e2c-4ece-9f25-32fc0337f0e7" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_76001842-8d43-4620-869a-4f8ac0c5fc10" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1_d487a91a-b601-4106-a468-535f19a1878f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_09447afb-6e2c-4ece-9f25-32fc0337f0e7" xlink:to="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1_d487a91a-b601-4106-a468-535f19a1878f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditAmortizationOfGainLossStatementOfIncomeOrComprehensiveIncomeExtensibleList_654ee0f3-736b-40dc-80ca-c91baa33a555" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditAmortizationOfGainLossStatementOfIncomeOrComprehensiveIncomeExtensibleList"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_09447afb-6e2c-4ece-9f25-32fc0337f0e7" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditAmortizationOfGainLossStatementOfIncomeOrComprehensiveIncomeExtensibleList_654ee0f3-736b-40dc-80ca-c91baa33a555" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_e0732f98-8318-4908-9ba9-57cf4d162e6d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_09447afb-6e2c-4ece-9f25-32fc0337f0e7" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_e0732f98-8318-4908-9ba9-57cf4d162e6d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_a95e22c5-d8fe-41b7-8e5c-6fcd24eb64bd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_09447afb-6e2c-4ece-9f25-32fc0337f0e7" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_a95e22c5-d8fe-41b7-8e5c-6fcd24eb64bd" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EmployeeBenefitPlansAssumptionsUsedforUSDefinedBenefitPlansTableDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EmployeeBenefitPlansAssumptionsUsedforUSDefinedBenefitPlansTableDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EmployeeBenefitPlansAssumptionsUsedforUSDefinedBenefitPlansTableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_3327d113-9ffc-44b4-983a-57cebaaaa068" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_ee4f6157-acd3-4d5e-8514-17ee053bbd87" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_3327d113-9ffc-44b4-983a-57cebaaaa068" xlink:to="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_ee4f6157-acd3-4d5e-8514-17ee053bbd87" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_27d5050c-77ec-4aff-96cd-61d80cbc2e9d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_ee4f6157-acd3-4d5e-8514-17ee053bbd87" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_27d5050c-77ec-4aff-96cd-61d80cbc2e9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_27d5050c-77ec-4aff-96cd-61d80cbc2e9d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_27d5050c-77ec-4aff-96cd-61d80cbc2e9d" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_27d5050c-77ec-4aff-96cd-61d80cbc2e9d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_e3599375-f502-4d0f-a7d3-078291c956da" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_27d5050c-77ec-4aff-96cd-61d80cbc2e9d" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_e3599375-f502-4d0f-a7d3-078291c956da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_9f4fde53-a594-4872-b98c-5af8e5c3231f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_e3599375-f502-4d0f-a7d3-078291c956da" xlink:to="loc_us-gaap_DomesticPlanMember_9f4fde53-a594-4872-b98c-5af8e5c3231f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_ad5ee719-8829-42e9-8a7b-5e56b47ae448" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_9f4fde53-a594-4872-b98c-5af8e5c3231f" xlink:to="loc_country_US_ad5ee719-8829-42e9-8a7b-5e56b47ae448" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_97588dce-5c3c-43ed-a214-5f60e49d1e1a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_3327d113-9ffc-44b4-983a-57cebaaaa068" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_97588dce-5c3c-43ed-a214-5f60e49d1e1a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_a7d88c26-52c9-42d1-83b3-03f0417e67b4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_3327d113-9ffc-44b4-983a-57cebaaaa068" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_a7d88c26-52c9-42d1-83b3-03f0417e67b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_3175e814-568e-4b0e-bbcd-4be895b846c1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_3327d113-9ffc-44b4-983a-57cebaaaa068" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_3175e814-568e-4b0e-bbcd-4be895b846c1" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EmployeeBenefitPlansAssumptionsUsedforNonUSDefinedPensionPlansTableDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EmployeeBenefitPlansAssumptionsUsedforNonUSDefinedPensionPlansTableDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EmployeeBenefitPlansAssumptionsUsedforNonUSDefinedPensionPlansTableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_a8db4185-12f4-4f08-b0c3-6260d37eb65e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_869470e8-9b8f-4f51-a057-37a441ad4dee" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_a8db4185-12f4-4f08-b0c3-6260d37eb65e" xlink:to="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_869470e8-9b8f-4f51-a057-37a441ad4dee" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_09dcd1ad-5225-46cc-baff-738b64d86914" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_869470e8-9b8f-4f51-a057-37a441ad4dee" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_09dcd1ad-5225-46cc-baff-738b64d86914" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_09dcd1ad-5225-46cc-baff-738b64d86914_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_09dcd1ad-5225-46cc-baff-738b64d86914" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_09dcd1ad-5225-46cc-baff-738b64d86914_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_42fe9a63-b554-4c3c-a9de-104699950b16" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_09dcd1ad-5225-46cc-baff-738b64d86914" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_42fe9a63-b554-4c3c-a9de-104699950b16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_d07f77b0-d58a-4ece-9f0a-371ff9bf2bc3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_42fe9a63-b554-4c3c-a9de-104699950b16" xlink:to="loc_us-gaap_ForeignPlanMember_d07f77b0-d58a-4ece-9f0a-371ff9bf2bc3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_1ac72c94-c327-4929-9a8a-866e6480b521" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_a8db4185-12f4-4f08-b0c3-6260d37eb65e" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate_1ac72c94-c327-4929-9a8a-866e6480b521" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_d445a38a-b3c9-4cc0-ba04-a5eb8a11e4e0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_a8db4185-12f4-4f08-b0c3-6260d37eb65e" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_d445a38a-b3c9-4cc0-ba04-a5eb8a11e4e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_dfc1603b-3daa-470e-abcd-f1f4a83d1391" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_a8db4185-12f4-4f08-b0c3-6260d37eb65e" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_dfc1603b-3daa-470e-abcd-f1f4a83d1391" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_e8459715-996f-4d45-b8ae-f29ec3b57158" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_a8db4185-12f4-4f08-b0c3-6260d37eb65e" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_e8459715-996f-4d45-b8ae-f29ec3b57158" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EmployeeBenefitPlansDefinedBenefitPlanChangeinBenefitObligationsandPlanAssetsTableDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EmployeeBenefitPlansDefinedBenefitPlanChangeinBenefitObligationsandPlanAssetsTableDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EmployeeBenefitPlansDefinedBenefitPlanChangeinBenefitObligationsandPlanAssetsTableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a42bb805-bba1-43fe-982c-9e4bf0bb137f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_951be7ef-ced9-432b-bf0f-6cd914a6cc86" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a42bb805-bba1-43fe-982c-9e4bf0bb137f" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_951be7ef-ced9-432b-bf0f-6cd914a6cc86" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_45bf59ae-6f14-46a7-95ab-5493f1e0a3d5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_951be7ef-ced9-432b-bf0f-6cd914a6cc86" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_45bf59ae-6f14-46a7-95ab-5493f1e0a3d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_45bf59ae-6f14-46a7-95ab-5493f1e0a3d5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_45bf59ae-6f14-46a7-95ab-5493f1e0a3d5" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_45bf59ae-6f14-46a7-95ab-5493f1e0a3d5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_d69e39fb-751e-44aa-bb79-4930b19fa2bb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_45bf59ae-6f14-46a7-95ab-5493f1e0a3d5" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_d69e39fb-751e-44aa-bb79-4930b19fa2bb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_84624c53-289d-4708-b6c5-656d0946f0a6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_d69e39fb-751e-44aa-bb79-4930b19fa2bb" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_84624c53-289d-4708-b6c5-656d0946f0a6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_b1dba319-4a55-43bf-bec3-7c83111eebd2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_951be7ef-ced9-432b-bf0f-6cd914a6cc86" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_b1dba319-4a55-43bf-bec3-7c83111eebd2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_b1dba319-4a55-43bf-bec3-7c83111eebd2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_b1dba319-4a55-43bf-bec3-7c83111eebd2" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_b1dba319-4a55-43bf-bec3-7c83111eebd2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_e8e1f1e3-c1a5-493d-b0bf-efd505280286" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_b1dba319-4a55-43bf-bec3-7c83111eebd2" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_e8e1f1e3-c1a5-493d-b0bf-efd505280286" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_713f0139-5312-4720-93f6-3d282241903a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_e8e1f1e3-c1a5-493d-b0bf-efd505280286" xlink:to="loc_us-gaap_ForeignPlanMember_713f0139-5312-4720-93f6-3d282241903a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_d7c28640-8350-4db9-a757-b649fb1d7298" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_e8e1f1e3-c1a5-493d-b0bf-efd505280286" xlink:to="loc_us-gaap_DomesticPlanMember_d7c28640-8350-4db9-a757-b649fb1d7298" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_e3a28ad9-07a8-4d7b-8d94-207c8119213c" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_d7c28640-8350-4db9-a757-b649fb1d7298" xlink:to="loc_country_US_e3a28ad9-07a8-4d7b-8d94-207c8119213c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_685fb101-3d18-4b58-b296-d8c9641aed59" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a42bb805-bba1-43fe-982c-9e4bf0bb137f" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_685fb101-3d18-4b58-b296-d8c9641aed59" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_a26facf0-5a56-4212-b2c6-684b0b3c720f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_685fb101-3d18-4b58-b296-d8c9641aed59" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligation_a26facf0-5a56-4212-b2c6-684b0b3c720f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_5525bffb-ce80-4afe-b4bb-4c46a1b424b0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_685fb101-3d18-4b58-b296-d8c9641aed59" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_5525bffb-ce80-4afe-b4bb-4c46a1b424b0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditInterestCostStatementOfIncomeOrComprehensiveIncomeExtensibleList_be4982ce-2a57-405a-9490-a4d59571a12e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditInterestCostStatementOfIncomeOrComprehensiveIncomeExtensibleList"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_685fb101-3d18-4b58-b296-d8c9641aed59" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCostCreditInterestCostStatementOfIncomeOrComprehensiveIncomeExtensibleList_be4982ce-2a57-405a-9490-a4d59571a12e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_c1f3741f-226f-40b4-acf3-e26a925b4e30" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_685fb101-3d18-4b58-b296-d8c9641aed59" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_c1f3741f-226f-40b4-acf3-e26a925b4e30" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant_2963f9d3-4f51-43f8-a5a9-de716e09ce8b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_685fb101-3d18-4b58-b296-d8c9641aed59" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant_2963f9d3-4f51-43f8-a5a9-de716e09ce8b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_fe6254d2-551b-4e93-92e9-6000b227333f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_685fb101-3d18-4b58-b296-d8c9641aed59" xlink:to="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_fe6254d2-551b-4e93-92e9-6000b227333f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_72fad798-09f3-4f9a-a810-42279cdec209" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_685fb101-3d18-4b58-b296-d8c9641aed59" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_72fad798-09f3-4f9a-a810-42279cdec209" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DefinedBenefitPlanBenefitObligationAnnuityPurchase_986dbfbb-5987-49e5-971c-3de25f63f3cf" xlink:href="trs-20241231.xsd#trs_DefinedBenefitPlanBenefitObligationAnnuityPurchase"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_685fb101-3d18-4b58-b296-d8c9641aed59" xlink:to="loc_trs_DefinedBenefitPlanBenefitObligationAnnuityPurchase_986dbfbb-5987-49e5-971c-3de25f63f3cf" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DefinedBenefitPlansSettlementsandCurtailments_c12e7d7e-3465-436c-8c15-c009e56ac70a" xlink:href="trs-20241231.xsd#trs_DefinedBenefitPlansSettlementsandCurtailments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_685fb101-3d18-4b58-b296-d8c9641aed59" xlink:to="loc_trs_DefinedBenefitPlansSettlementsandCurtailments_c12e7d7e-3465-436c-8c15-c009e56ac70a" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation_559cb5a3-797a-4d10-9847-c9c6b444ccfe" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_685fb101-3d18-4b58-b296-d8c9641aed59" xlink:to="loc_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation_559cb5a3-797a-4d10-9847-c9c6b444ccfe" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_774a74ea-922d-43be-ba1c-41f9de5355cc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a6687bac-1d10-479c-902f-bd6d226b0dfd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a42bb805-bba1-43fe-982c-9e4bf0bb137f" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a6687bac-1d10-479c-902f-bd6d226b0dfd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_3b87db05-bd61-43e2-acbf-c1c1e88669f1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a6687bac-1d10-479c-902f-bd6d226b0dfd" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_3b87db05-bd61-43e2-acbf-c1c1e88669f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_0b3bfade-e391-40ce-a735-2ddbc3973bb6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a6687bac-1d10-479c-902f-bd6d226b0dfd" xlink:to="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_0b3bfade-e391-40ce-a735-2ddbc3973bb6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_5e7dbeb9-425e-4b23-b40d-0a7484339cba" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a6687bac-1d10-479c-902f-bd6d226b0dfd" xlink:to="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_5e7dbeb9-425e-4b23-b40d-0a7484339cba" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsContributionsByPlanParticipant_6e630a91-cbd6-403d-8909-b24590fb5b08" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPlanAssetsContributionsByPlanParticipant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a6687bac-1d10-479c-902f-bd6d226b0dfd" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsContributionsByPlanParticipant_6e630a91-cbd6-403d-8909-b24590fb5b08" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_3ce305de-943a-4e49-8716-b847eec3aa97" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a6687bac-1d10-479c-902f-bd6d226b0dfd" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_3ce305de-943a-4e49-8716-b847eec3aa97" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DefinedBenefitPlanPlanAssetsAnnuityPurchase_2609410c-14b7-46d7-8c26-a069ac9cca7b" xlink:href="trs-20241231.xsd#trs_DefinedBenefitPlanPlanAssetsAnnuityPurchase"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a6687bac-1d10-479c-902f-bd6d226b0dfd" xlink:to="loc_trs_DefinedBenefitPlanPlanAssetsAnnuityPurchase_2609410c-14b7-46d7-8c26-a069ac9cca7b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanSettlementsPlanAssets_0860527e-e8e4-4e31-9c00-bffdde308674" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanSettlementsPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a6687bac-1d10-479c-902f-bd6d226b0dfd" xlink:to="loc_us-gaap_DefinedBenefitPlanSettlementsPlanAssets_0860527e-e8e4-4e31-9c00-bffdde308674" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss_47a09a9a-e91a-490b-a41d-e52b3124633a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a6687bac-1d10-479c-902f-bd6d226b0dfd" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss_47a09a9a-e91a-490b-a41d-e52b3124633a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_72421bcd-06fd-45e7-b816-a8668cf14498" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlanAbstract_0d3c993d-6b9a-4e7d-a586-c927a7825985" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanFundedStatusOfPlanAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a42bb805-bba1-43fe-982c-9e4bf0bb137f" xlink:to="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlanAbstract_0d3c993d-6b9a-4e7d-a586-c927a7825985" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_176e61b9-910a-413e-b326-ad530bc87da6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanFundedStatusOfPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlanAbstract_0d3c993d-6b9a-4e7d-a586-c927a7825985" xlink:to="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_176e61b9-910a-413e-b326-ad530bc87da6" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EmployeeBenefitPlansAmountsRecognizedonBalanceSheetTableDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EmployeeBenefitPlansAmountsRecognizedonBalanceSheetTableDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EmployeeBenefitPlansAmountsRecognizedonBalanceSheetTableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_d34b0f0f-8559-494f-9abe-0beeff98d687" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0c96e766-696b-400e-b4d6-c8644893e309" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_d34b0f0f-8559-494f-9abe-0beeff98d687" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0c96e766-696b-400e-b4d6-c8644893e309" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_421820e8-dc2f-4123-8471-4dcee77dbbdc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0c96e766-696b-400e-b4d6-c8644893e309" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_421820e8-dc2f-4123-8471-4dcee77dbbdc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_421820e8-dc2f-4123-8471-4dcee77dbbdc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_421820e8-dc2f-4123-8471-4dcee77dbbdc" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_421820e8-dc2f-4123-8471-4dcee77dbbdc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_d8d0b49f-ae99-48bc-832b-3d7854590367" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_421820e8-dc2f-4123-8471-4dcee77dbbdc" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_d8d0b49f-ae99-48bc-832b-3d7854590367" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_333fc7b6-ee4d-42b0-8370-ec79e1cb2140" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_d8d0b49f-ae99-48bc-832b-3d7854590367" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_333fc7b6-ee4d-42b0-8370-ec79e1cb2140" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_d764ac7e-8ca8-4082-ad0f-08f9310dcf8a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_d34b0f0f-8559-494f-9abe-0beeff98d687" xlink:to="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_d764ac7e-8ca8-4082-ad0f-08f9310dcf8a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_f0393101-9706-4ce2-843b-9eec0cbdab9e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_d34b0f0f-8559-494f-9abe-0beeff98d687" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_f0393101-9706-4ce2-843b-9eec0cbdab9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_8ce0c636-a628-44fc-b268-9d9b6f3adc05" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_f0393101-9706-4ce2-843b-9eec0cbdab9e" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_8ce0c636-a628-44fc-b268-9d9b6f3adc05" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_53aa48ef-79ce-4c71-b9c0-1fb5afb37f72" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_f0393101-9706-4ce2-843b-9eec0cbdab9e" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_53aa48ef-79ce-4c71-b9c0-1fb5afb37f72" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet_26e2ab29-8ced-442c-b826-59900f0c55d1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_f0393101-9706-4ce2-843b-9eec0cbdab9e" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet_26e2ab29-8ced-442c-b826-59900f0c55d1" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EmployeeBenefitPlansAmountsRecognizedinAccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EmployeeBenefitPlansAmountsRecognizedinAccumulatedOtherComprehensiveIncomeLossDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EmployeeBenefitPlansAmountsRecognizedinAccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_dd8d93e1-94a5-4a1e-ad85-ef4269a3a9ad" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_64d1d410-8ded-4bac-8263-610d7b60919c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_dd8d93e1-94a5-4a1e-ad85-ef4269a3a9ad" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_64d1d410-8ded-4bac-8263-610d7b60919c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_07931e1d-2d48-458a-b0ec-efa881a79d6f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_64d1d410-8ded-4bac-8263-610d7b60919c" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_07931e1d-2d48-458a-b0ec-efa881a79d6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_07931e1d-2d48-458a-b0ec-efa881a79d6f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_07931e1d-2d48-458a-b0ec-efa881a79d6f" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_07931e1d-2d48-458a-b0ec-efa881a79d6f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_6e07fc9a-01e6-44fe-a72e-403430a24da2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_07931e1d-2d48-458a-b0ec-efa881a79d6f" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_6e07fc9a-01e6-44fe-a72e-403430a24da2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_5c5d76bf-d643-48a7-989d-8fc4f0e80d52" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_6e07fc9a-01e6-44fe-a72e-403430a24da2" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_5c5d76bf-d643-48a7-989d-8fc4f0e80d52" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossAfterTaxAbstract_c750c253-a3a4-4254-9d37-d494130a1fb8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossAfterTaxAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_dd8d93e1-94a5-4a1e-ad85-ef4269a3a9ad" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossAfterTaxAbstract_c750c253-a3a4-4254-9d37-d494130a1fb8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax_6e1c8fe0-9dcd-47c2-aeb1-2dd19706748f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossAfterTaxAbstract_c750c253-a3a4-4254-9d37-d494130a1fb8" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditAfterTax_6e1c8fe0-9dcd-47c2-aeb1-2dd19706748f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax_e30a7cc6-0bf6-4dc2-b9c2-f9fc6ccad5fd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossAfterTaxAbstract_c750c253-a3a4-4254-9d37-d494130a1fb8" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesAfterTax_e30a7cc6-0bf6-4dc2-b9c2-f9fc6ccad5fd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax_c6c0958b-a309-41b3-b9d1-59eabb44992b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeLossAfterTaxAbstract_c750c253-a3a4-4254-9d37-d494130a1fb8" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossDefinedBenefitPensionAndOtherPostretirementPlansNetOfTax_c6c0958b-a309-41b3-b9d1-59eabb44992b" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EmployeeBenefitPlansPlanswithBenefitObligationsinExcessofAssetsTableDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EmployeeBenefitPlansPlanswithBenefitObligationsinExcessofAssetsTableDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EmployeeBenefitPlansPlanswithBenefitObligationsinExcessofAssetsTableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_6e5f322d-5d1c-44fa-b69a-ded69473ee7d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_20a3f1f9-4b55-48bd-84d2-227d90e8b209" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_6e5f322d-5d1c-44fa-b69a-ded69473ee7d" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_20a3f1f9-4b55-48bd-84d2-227d90e8b209" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_7823f563-90a7-42bc-b3e9-b49a61a50098" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_20a3f1f9-4b55-48bd-84d2-227d90e8b209" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_7823f563-90a7-42bc-b3e9-b49a61a50098" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_7823f563-90a7-42bc-b3e9-b49a61a50098_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_7823f563-90a7-42bc-b3e9-b49a61a50098" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_7823f563-90a7-42bc-b3e9-b49a61a50098_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_477ef834-41a4-4401-9c3a-d3e8d2775e37" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_7823f563-90a7-42bc-b3e9-b49a61a50098" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_477ef834-41a4-4401-9c3a-d3e8d2775e37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_161088d6-3207-4811-9304-2293770db26a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_477ef834-41a4-4401-9c3a-d3e8d2775e37" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_161088d6-3207-4811-9304-2293770db26a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_c1663640-a8a3-49a7-afa1-4718b90c8a8e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_6e5f322d-5d1c-44fa-b69a-ded69473ee7d" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_c1663640-a8a3-49a7-afa1-4718b90c8a8e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_ef228b67-3ae9-4062-b841-d9cdf277af73" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_6e5f322d-5d1c-44fa-b69a-ded69473ee7d" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligation_ef228b67-3ae9-4062-b841-d9cdf277af73" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation_fd6edf99-a80b-46d3-ac45-b0965c0dd185" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_6e5f322d-5d1c-44fa-b69a-ded69473ee7d" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation_fd6edf99-a80b-46d3-ac45-b0965c0dd185" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation_d8efeaf3-ee10-49cd-93e1-d09971590d2e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_6e5f322d-5d1c-44fa-b69a-ded69473ee7d" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation_d8efeaf3-ee10-49cd-93e1-d09971590d2e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets_a54467fb-7f4e-46d7-8181-f12afa8c49f9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_6e5f322d-5d1c-44fa-b69a-ded69473ee7d" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets_a54467fb-7f4e-46d7-8181-f12afa8c49f9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets_5fb9aa18-f2ea-47f3-a107-4392078e1d70" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_6e5f322d-5d1c-44fa-b69a-ded69473ee7d" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets_5fb9aa18-f2ea-47f3-a107-4392078e1d70" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EmployeeBenefitPlansEffectofChangeinDiscountRateandExpectedReturnonPlanAssetsTableDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EmployeeBenefitPlansEffectofChangeinDiscountRateandExpectedReturnonPlanAssetsTableDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EmployeeBenefitPlansEffectofChangeinDiscountRateandExpectedReturnonPlanAssetsTableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1efb0783-dcd8-4bc2-8ab3-1b1a008737e1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_c2c31db7-c4a6-47e3-b8ee-bb871496c421" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1efb0783-dcd8-4bc2-8ab3-1b1a008737e1" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_c2c31db7-c4a6-47e3-b8ee-bb871496c421" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_9d681c19-bf7d-480c-8175-1ff9fb74bb08" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_c2c31db7-c4a6-47e3-b8ee-bb871496c421" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_9d681c19-bf7d-480c-8175-1ff9fb74bb08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_9d681c19-bf7d-480c-8175-1ff9fb74bb08_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_9d681c19-bf7d-480c-8175-1ff9fb74bb08" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_9d681c19-bf7d-480c-8175-1ff9fb74bb08_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_a3ef4f68-9acb-4142-b712-2889d9b7d700" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_9d681c19-bf7d-480c-8175-1ff9fb74bb08" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_a3ef4f68-9acb-4142-b712-2889d9b7d700" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_d8474c2a-293e-43a7-b490-63be5021e1db" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_a3ef4f68-9acb-4142-b712-2889d9b7d700" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_d8474c2a-293e-43a7-b490-63be5021e1db" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointChangeInDiscountRateAbstractAbstract_2f6f0d66-14b2-4dd0-ac53-9314b1367476" xlink:href="trs-20241231.xsd#trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointChangeInDiscountRateAbstractAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1efb0783-dcd8-4bc2-8ab3-1b1a008737e1" xlink:to="loc_trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointChangeInDiscountRateAbstractAbstract_2f6f0d66-14b2-4dd0-ac53-9314b1367476" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointIncreaseInDiscountRateOnBenefitObligation_8fa0ce4b-b1bf-4d15-a56f-ef9ab10d08e7" xlink:href="trs-20241231.xsd#trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointIncreaseInDiscountRateOnBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointChangeInDiscountRateAbstractAbstract_2f6f0d66-14b2-4dd0-ac53-9314b1367476" xlink:to="loc_trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointIncreaseInDiscountRateOnBenefitObligation_8fa0ce4b-b1bf-4d15-a56f-ef9ab10d08e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointDecreaseInDiscountRateOnBenefitObligation_af74777f-7f55-4ad3-8301-39f11951c313" xlink:href="trs-20241231.xsd#trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointDecreaseInDiscountRateOnBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointChangeInDiscountRateAbstractAbstract_2f6f0d66-14b2-4dd0-ac53-9314b1367476" xlink:to="loc_trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointDecreaseInDiscountRateOnBenefitObligation_af74777f-7f55-4ad3-8301-39f11951c313" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointIncreaseInDiscountRateOnExpense_7a8ce724-7a7f-4a88-af2a-1613022ad814" xlink:href="trs-20241231.xsd#trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointIncreaseInDiscountRateOnExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointChangeInDiscountRateAbstractAbstract_2f6f0d66-14b2-4dd0-ac53-9314b1367476" xlink:to="loc_trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointIncreaseInDiscountRateOnExpense_7a8ce724-7a7f-4a88-af2a-1613022ad814" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointDecreaseInDiscountRateOnExpense_84c761b5-0d9a-46d3-b5b4-66593476db3d" xlink:href="trs-20241231.xsd#trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointDecreaseInDiscountRateOnExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointChangeInDiscountRateAbstractAbstract_2f6f0d66-14b2-4dd0-ac53-9314b1367476" xlink:to="loc_trs_DefinedBenefitPlanEffectOfTwentyFiveBasisPointDecreaseInDiscountRateOnExpense_84c761b5-0d9a-46d3-b5b4-66593476db3d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DefinedBenefitPlanEffectOfFiftyBasisPointChangeInExpectedReturnOnPlanAssetsAbstractAbstract_ec229a1c-02e3-442d-a99e-5f852ce34543" xlink:href="trs-20241231.xsd#trs_DefinedBenefitPlanEffectOfFiftyBasisPointChangeInExpectedReturnOnPlanAssetsAbstractAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_1efb0783-dcd8-4bc2-8ab3-1b1a008737e1" xlink:to="loc_trs_DefinedBenefitPlanEffectOfFiftyBasisPointChangeInExpectedReturnOnPlanAssetsAbstractAbstract_ec229a1c-02e3-442d-a99e-5f852ce34543" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DefinedBenefitPlanEffectOfFiftyBasisPointIncreaseInExpectedReturnOnPlanAssetsOnExpense_fd58c9f7-585b-4b25-81af-0346eedf5e9c" xlink:href="trs-20241231.xsd#trs_DefinedBenefitPlanEffectOfFiftyBasisPointIncreaseInExpectedReturnOnPlanAssetsOnExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DefinedBenefitPlanEffectOfFiftyBasisPointChangeInExpectedReturnOnPlanAssetsAbstractAbstract_ec229a1c-02e3-442d-a99e-5f852ce34543" xlink:to="loc_trs_DefinedBenefitPlanEffectOfFiftyBasisPointIncreaseInExpectedReturnOnPlanAssetsOnExpense_fd58c9f7-585b-4b25-81af-0346eedf5e9c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DefinedBenefitPlanEffectOfFiftyBasisPointDecreaseInExpectedReturnOnPlanAssetsOnExpense_17ee6267-b9fb-4576-a093-897e4c76c954" xlink:href="trs-20241231.xsd#trs_DefinedBenefitPlanEffectOfFiftyBasisPointDecreaseInExpectedReturnOnPlanAssetsOnExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DefinedBenefitPlanEffectOfFiftyBasisPointChangeInExpectedReturnOnPlanAssetsAbstractAbstract_ec229a1c-02e3-442d-a99e-5f852ce34543" xlink:to="loc_trs_DefinedBenefitPlanEffectOfFiftyBasisPointDecreaseInExpectedReturnOnPlanAssetsOnExpense_17ee6267-b9fb-4576-a093-897e4c76c954" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EmployeeBenefitPlansWeightedAverageAssetAllocationbyPensionPlanDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EmployeeBenefitPlansWeightedAverageAssetAllocationbyPensionPlanDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EmployeeBenefitPlansWeightedAverageAssetAllocationbyPensionPlanDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c438a027-a5c8-4c3c-bd4b-1c93a166fe0c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_d0467f91-e189-49d9-a457-534c2c65c832" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c438a027-a5c8-4c3c-bd4b-1c93a166fe0c" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_d0467f91-e189-49d9-a457-534c2c65c832" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_f6abf6dc-067e-4b63-9a75-4a4759359135" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_d0467f91-e189-49d9-a457-534c2c65c832" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_f6abf6dc-067e-4b63-9a75-4a4759359135" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_f6abf6dc-067e-4b63-9a75-4a4759359135_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_f6abf6dc-067e-4b63-9a75-4a4759359135" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_f6abf6dc-067e-4b63-9a75-4a4759359135_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_a5a669ef-8931-40e8-b196-bee2fdd5f287" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_f6abf6dc-067e-4b63-9a75-4a4759359135" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_a5a669ef-8931-40e8-b196-bee2fdd5f287" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_1564066e-4724-4eb6-a346-808f0f47fc3f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_a5a669ef-8931-40e8-b196-bee2fdd5f287" xlink:to="loc_us-gaap_ForeignPlanMember_1564066e-4724-4eb6-a346-808f0f47fc3f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_d712e0cd-86a3-4e47-9c98-d8013c582026" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_a5a669ef-8931-40e8-b196-bee2fdd5f287" xlink:to="loc_us-gaap_DomesticPlanMember_d712e0cd-86a3-4e47-9c98-d8013c582026" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_b3e094ea-07db-4c22-9a7c-340be3ca1c14" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_d712e0cd-86a3-4e47-9c98-d8013c582026" xlink:to="loc_country_US_b3e094ea-07db-4c22-9a7c-340be3ca1c14" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_410f1dec-1af2-4e88-8bcb-811beb77a66f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_d0467f91-e189-49d9-a457-534c2c65c832" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_410f1dec-1af2-4e88-8bcb-811beb77a66f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_410f1dec-1af2-4e88-8bcb-811beb77a66f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_410f1dec-1af2-4e88-8bcb-811beb77a66f" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_410f1dec-1af2-4e88-8bcb-811beb77a66f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_26505b4e-f21e-4721-b5c7-909f861a35aa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_410f1dec-1af2-4e88-8bcb-811beb77a66f" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_26505b4e-f21e-4721-b5c7-909f861a35aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesMember_962ac034-3d3d-4050-b347-108e69a7aa52" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_26505b4e-f21e-4721-b5c7-909f861a35aa" xlink:to="loc_us-gaap_EquitySecuritiesMember_962ac034-3d3d-4050-b347-108e69a7aa52" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FixedIncomeFundsMember_f186ee0c-d8e2-4f9e-9108-6fd6f4eafa16" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FixedIncomeFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_26505b4e-f21e-4721-b5c7-909f861a35aa" xlink:to="loc_us-gaap_FixedIncomeFundsMember_f186ee0c-d8e2-4f9e-9108-6fd6f4eafa16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalancedFundsMember_1bab3eb7-1d35-4bb7-9abe-5151310abedf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalancedFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_26505b4e-f21e-4721-b5c7-909f861a35aa" xlink:to="loc_us-gaap_BalancedFundsMember_1bab3eb7-1d35-4bb7-9abe-5151310abedf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsMember_51df358c-432a-4532-945a-fc3bd6832993" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_26505b4e-f21e-4721-b5c7-909f861a35aa" xlink:to="loc_us-gaap_CashAndCashEquivalentsMember_51df358c-432a-4532-945a-fc3bd6832993" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_InsuranceContractMember_8387ee84-280f-4e9c-9bc0-3f35c1241d2a" xlink:href="trs-20241231.xsd#trs_InsuranceContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_26505b4e-f21e-4721-b5c7-909f861a35aa" xlink:to="loc_trs_InsuranceContractMember_8387ee84-280f-4e9c-9bc0-3f35c1241d2a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations_f37377cf-9240-4658-af81-b7d5a275fa61" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c438a027-a5c8-4c3c-bd4b-1c93a166fe0c" xlink:to="loc_us-gaap_DefinedBenefitPlanWeightedAverageAssetAllocations_f37377cf-9240-4658-af81-b7d5a275fa61" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_c944dee0-4700-4055-ad57-7489fc7c0e88" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c438a027-a5c8-4c3c-bd4b-1c93a166fe0c" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_c944dee0-4700-4055-ad57-7489fc7c0e88" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EmployeeBenefitPlansPensionPlanAssetsFairValueHierarchyTableDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EmployeeBenefitPlansPensionPlanAssetsFairValueHierarchyTableDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EmployeeBenefitPlansPensionPlanAssetsFairValueHierarchyTableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_fe2aced3-f5e6-4321-bcba-d917f198112a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_704a7031-57d9-45f4-98ef-cea3ffaa244b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_fe2aced3-f5e6-4321-bcba-d917f198112a" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_704a7031-57d9-45f4-98ef-cea3ffaa244b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_d4b5ced4-9cb8-4b9a-a112-0df02c3d247a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_704a7031-57d9-45f4-98ef-cea3ffaa244b" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_d4b5ced4-9cb8-4b9a-a112-0df02c3d247a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_d4b5ced4-9cb8-4b9a-a112-0df02c3d247a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_d4b5ced4-9cb8-4b9a-a112-0df02c3d247a" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_d4b5ced4-9cb8-4b9a-a112-0df02c3d247a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1697d3cb-cb4d-4f1b-a790-a6cf21cc156a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_d4b5ced4-9cb8-4b9a-a112-0df02c3d247a" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1697d3cb-cb4d-4f1b-a790-a6cf21cc156a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_17dcda6a-47cb-4280-ae7e-fe161bf5bba0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_1697d3cb-cb4d-4f1b-a790-a6cf21cc156a" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_17dcda6a-47cb-4280-ae7e-fe161bf5bba0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_5aa2ea23-9e16-4055-8916-1f983dcbcfd7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_704a7031-57d9-45f4-98ef-cea3ffaa244b" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_5aa2ea23-9e16-4055-8916-1f983dcbcfd7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_5aa2ea23-9e16-4055-8916-1f983dcbcfd7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_5aa2ea23-9e16-4055-8916-1f983dcbcfd7" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_5aa2ea23-9e16-4055-8916-1f983dcbcfd7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_597ecd6f-22b1-463d-8df3-c42213cb922c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_5aa2ea23-9e16-4055-8916-1f983dcbcfd7" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_597ecd6f-22b1-463d-8df3-c42213cb922c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FixedIncomeFundsMember_753c238f-b8f3-4b16-b81a-d57597d26d7d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FixedIncomeFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_597ecd6f-22b1-463d-8df3-c42213cb922c" xlink:to="loc_us-gaap_FixedIncomeFundsMember_753c238f-b8f3-4b16-b81a-d57597d26d7d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsMember_ea482bab-91d3-4c51-a74c-13cf48ecd6d7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_597ecd6f-22b1-463d-8df3-c42213cb922c" xlink:to="loc_us-gaap_CashAndCashEquivalentsMember_ea482bab-91d3-4c51-a74c-13cf48ecd6d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesMember_27602ce4-e532-4787-add5-aa144fed745b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquitySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_597ecd6f-22b1-463d-8df3-c42213cb922c" xlink:to="loc_us-gaap_EquitySecuritiesMember_27602ce4-e532-4787-add5-aa144fed745b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalancedFundsMember_0f9fab4d-21f7-4e04-8495-d7628b89f9d9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BalancedFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_597ecd6f-22b1-463d-8df3-c42213cb922c" xlink:to="loc_us-gaap_BalancedFundsMember_0f9fab4d-21f7-4e04-8495-d7628b89f9d9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignGovernmentDebtSecuritiesMember_aa343e65-48e0-4e86-8d95-f6ac06051d44" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignGovernmentDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_597ecd6f-22b1-463d-8df3-c42213cb922c" xlink:to="loc_us-gaap_ForeignGovernmentDebtSecuritiesMember_aa343e65-48e0-4e86-8d95-f6ac06051d44" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanCashMember_aaaa7dcb-721a-44e2-a1d0-b8a8657a3979" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanCashMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_597ecd6f-22b1-463d-8df3-c42213cb922c" xlink:to="loc_us-gaap_DefinedBenefitPlanCashMember_aaaa7dcb-721a-44e2-a1d0-b8a8657a3979" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_InsuranceContractMember_37336251-19e9-4498-828f-893831b46735" xlink:href="trs-20241231.xsd#trs_InsuranceContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_597ecd6f-22b1-463d-8df3-c42213cb922c" xlink:to="loc_trs_InsuranceContractMember_37336251-19e9-4498-828f-893831b46735" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_b823711d-4a04-4cee-89fc-2067eec50147" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_704a7031-57d9-45f4-98ef-cea3ffaa244b" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_b823711d-4a04-4cee-89fc-2067eec50147" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_b823711d-4a04-4cee-89fc-2067eec50147_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_b823711d-4a04-4cee-89fc-2067eec50147" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_b823711d-4a04-4cee-89fc-2067eec50147_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9c1f2982-4e44-4cf0-9449-c00083be06c7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_b823711d-4a04-4cee-89fc-2067eec50147" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9c1f2982-4e44-4cf0-9449-c00083be06c7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_7dc6dcf8-fc6d-44c4-8577-c5bd539177a7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9c1f2982-4e44-4cf0-9449-c00083be06c7" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_7dc6dcf8-fc6d-44c4-8577-c5bd539177a7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_53cef3d3-ee18-43e1-ad0b-f7c6cf4a34d5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9c1f2982-4e44-4cf0-9449-c00083be06c7" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_53cef3d3-ee18-43e1-ad0b-f7c6cf4a34d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_188997b1-3480-42c0-b6ab-a4276d5b6849" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_9c1f2982-4e44-4cf0-9449-c00083be06c7" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_188997b1-3480-42c0-b6ab-a4276d5b6849" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_98cd2e9c-c49f-4c0c-ae1f-6f776fea6a4a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_fe2aced3-f5e6-4321-bcba-d917f198112a" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_98cd2e9c-c49f-4c0c-ae1f-6f776fea6a4a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DefinedBenefitPlanFairValueofPlanAssetsNotSubjecttoLeveling_6dde26c5-2e26-4eb7-af6c-14ffdec9a291" xlink:href="trs-20241231.xsd#trs_DefinedBenefitPlanFairValueofPlanAssetsNotSubjecttoLeveling"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_fe2aced3-f5e6-4321-bcba-d917f198112a" xlink:to="loc_trs_DefinedBenefitPlanFairValueofPlanAssetsNotSubjecttoLeveling_6dde26c5-2e26-4eb7-af6c-14ffdec9a291" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DefinedBenefitPlanFairValueofPlanAssetsSubjecttoLeveling_48784282-9f9d-4c9a-9a5e-68e1156e774b" xlink:href="trs-20241231.xsd#trs_DefinedBenefitPlanFairValueofPlanAssetsSubjecttoLeveling"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_fe2aced3-f5e6-4321-bcba-d917f198112a" xlink:to="loc_trs_DefinedBenefitPlanFairValueofPlanAssetsSubjecttoLeveling_48784282-9f9d-4c9a-9a5e-68e1156e774b" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EmployeeBenefitPlansPlanAssetsLevel3ReconciliationDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EmployeeBenefitPlansPlanAssetsLevel3ReconciliationDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EmployeeBenefitPlansPlanAssetsLevel3ReconciliationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationLineItems_0664ac0d-f594-4ccb-996a-26efa230053c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationTable_8b22ce2c-6250-4640-a659-721da53c2ac0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationLineItems_0664ac0d-f594-4ccb-996a-26efa230053c" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationTable_8b22ce2c-6250-4640-a659-721da53c2ac0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_4aa04480-4cb2-42dd-a904-1e359ed16ecd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationTable_8b22ce2c-6250-4640-a659-721da53c2ac0" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_4aa04480-4cb2-42dd-a904-1e359ed16ecd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_4aa04480-4cb2-42dd-a904-1e359ed16ecd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_4aa04480-4cb2-42dd-a904-1e359ed16ecd" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_4aa04480-4cb2-42dd-a904-1e359ed16ecd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_b59426f7-87ad-4746-8dce-44ae88659b15" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_4aa04480-4cb2-42dd-a904-1e359ed16ecd" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_b59426f7-87ad-4746-8dce-44ae88659b15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_e410e074-0454-4aff-b6d5-defd5c2cad90" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_b59426f7-87ad-4746-8dce-44ae88659b15" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_e410e074-0454-4aff-b6d5-defd5c2cad90" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4e113de2-752f-4239-9677-34065166a270" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationTable_8b22ce2c-6250-4640-a659-721da53c2ac0" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4e113de2-752f-4239-9677-34065166a270" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4e113de2-752f-4239-9677-34065166a270_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4e113de2-752f-4239-9677-34065166a270" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_4e113de2-752f-4239-9677-34065166a270_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_b357250f-305e-4ab4-b796-adedb52ec3df" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_4e113de2-752f-4239-9677-34065166a270" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_b357250f-305e-4ab4-b796-adedb52ec3df" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_9d354ce9-79fc-45cf-a368-f114de43abc5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_b357250f-305e-4ab4-b796-adedb52ec3df" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_9d354ce9-79fc-45cf-a368-f114de43abc5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_35f462b3-5e95-4f43-a1d8-3a2b29f96b06" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationTable_8b22ce2c-6250-4640-a659-721da53c2ac0" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_35f462b3-5e95-4f43-a1d8-3a2b29f96b06" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_35f462b3-5e95-4f43-a1d8-3a2b29f96b06_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_35f462b3-5e95-4f43-a1d8-3a2b29f96b06" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_35f462b3-5e95-4f43-a1d8-3a2b29f96b06_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_fab537bf-30e9-401e-8077-ed5b5e1545b0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_35f462b3-5e95-4f43-a1d8-3a2b29f96b06" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_fab537bf-30e9-401e-8077-ed5b5e1545b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_InsuranceContractMember_8dbe5ec4-2e2a-47fe-bf97-1e680b686e47" xlink:href="trs-20241231.xsd#trs_InsuranceContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_fab537bf-30e9-401e-8077-ed5b5e1545b0" xlink:to="loc_trs_InsuranceContractMember_8dbe5ec4-2e2a-47fe-bf97-1e680b686e47" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationIncreaseForPurchase_8d2ac36b-4c99-4143-92f1-3226a60ca788" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationIncreaseForPurchase"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationLineItems_0664ac0d-f594-4ccb-996a-26efa230053c" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationIncreaseForPurchase_8d2ac36b-4c99-4143-92f1-3226a60ca788" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_5a2285cb-bb67-4f32-bb88-7638b03329b2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationLineItems_0664ac0d-f594-4ccb-996a-26efa230053c" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_5a2285cb-bb67-4f32-bb88-7638b03329b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsLevel3ReconciliationPeriodIncreaseDecrease_38b3c670-9e05-489e-bed0-64362537821f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsLevel3ReconciliationPeriodIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanPlanAssetsLevel3ReconciliationLineItems_0664ac0d-f594-4ccb-996a-26efa230053c" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsLevel3ReconciliationPeriodIncreaseDecrease_38b3c670-9e05-489e-bed0-64362537821f" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EmployeeBenefitPlansFutureBenefitPaymentsTableDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EmployeeBenefitPlansFutureBenefitPaymentsTableDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EmployeeBenefitPlansFutureBenefitPaymentsTableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_f76b568d-7098-4e91-810e-fd36e7dfcf8e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2b92fed2-81b2-4c99-aa84-f818fe242f1b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_f76b568d-7098-4e91-810e-fd36e7dfcf8e" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2b92fed2-81b2-4c99-aa84-f818fe242f1b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_2132102f-8d82-41ac-999c-54e0c4041677" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2b92fed2-81b2-4c99-aa84-f818fe242f1b" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_2132102f-8d82-41ac-999c-54e0c4041677" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_2132102f-8d82-41ac-999c-54e0c4041677_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_2132102f-8d82-41ac-999c-54e0c4041677" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_2132102f-8d82-41ac-999c-54e0c4041677_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_5b11df65-7fdf-4856-b7fc-b9ec0af38d1a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_2132102f-8d82-41ac-999c-54e0c4041677" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_5b11df65-7fdf-4856-b7fc-b9ec0af38d1a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_a49349ee-0231-4d00-a568-1bfbed578b4e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_5b11df65-7fdf-4856-b7fc-b9ec0af38d1a" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_a49349ee-0231-4d00-a568-1bfbed578b4e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_6195f0e7-374d-41e2-9eec-7d5357626be0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_f76b568d-7098-4e91-810e-fd36e7dfcf8e" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_6195f0e7-374d-41e2-9eec-7d5357626be0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_c6f2d06f-f065-459b-9303-56d1849aafc3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_f76b568d-7098-4e91-810e-fd36e7dfcf8e" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_c6f2d06f-f065-459b-9303-56d1849aafc3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_cc632921-242e-4b88-90a3-134010480cd0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_f76b568d-7098-4e91-810e-fd36e7dfcf8e" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_cc632921-242e-4b88-90a3-134010480cd0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_6981f602-fdb5-482b-be93-3aeb3adf8f24" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_f76b568d-7098-4e91-810e-fd36e7dfcf8e" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_6981f602-fdb5-482b-be93-3aeb3adf8f24" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_0e80cf05-d532-406a-9a2a-5a5178b555f2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_f76b568d-7098-4e91-810e-fd36e7dfcf8e" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_0e80cf05-d532-406a-9a2a-5a5178b555f2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_adbccc9e-ec62-4869-ac55-5c8d0240b92f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_f76b568d-7098-4e91-810e-fd36e7dfcf8e" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_adbccc9e-ec62-4869-ac55-5c8d0240b92f" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EquityAwardsEquityAwardsNarrativeDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EquityAwardsEquityAwardsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EquityAwardsEquityAwardsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01baa38b-0004-4344-bb43-c9dad7830d54" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_630b000e-fd99-4e70-9787-eb79ed229437" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01baa38b-0004-4344-bb43-c9dad7830d54" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_630b000e-fd99-4e70-9787-eb79ed229437" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_MetricTypeAxis_3d39b8e2-d872-4c23-ae57-416990a7cba4" xlink:href="trs-20241231.xsd#trs_MetricTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_630b000e-fd99-4e70-9787-eb79ed229437" xlink:to="loc_trs_MetricTypeAxis_3d39b8e2-d872-4c23-ae57-416990a7cba4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_MetricTypeDomain_3d39b8e2-d872-4c23-ae57-416990a7cba4_default" xlink:href="trs-20241231.xsd#trs_MetricTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_MetricTypeAxis_3d39b8e2-d872-4c23-ae57-416990a7cba4" xlink:to="loc_trs_MetricTypeDomain_3d39b8e2-d872-4c23-ae57-416990a7cba4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_MetricTypeDomain_25bcd4f0-3c85-4917-8081-469a5586ff96" xlink:href="trs-20241231.xsd#trs_MetricTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_MetricTypeAxis_3d39b8e2-d872-4c23-ae57-416990a7cba4" xlink:to="loc_trs_MetricTypeDomain_25bcd4f0-3c85-4917-8081-469a5586ff96" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_a2379bef-c419-472e-8474-91fe9b4e2ac4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_630b000e-fd99-4e70-9787-eb79ed229437" xlink:to="loc_us-gaap_StatementClassOfStockAxis_a2379bef-c419-472e-8474-91fe9b4e2ac4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_a2379bef-c419-472e-8474-91fe9b4e2ac4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_a2379bef-c419-472e-8474-91fe9b4e2ac4" xlink:to="loc_us-gaap_ClassOfStockDomain_a2379bef-c419-472e-8474-91fe9b4e2ac4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_84a11624-d870-4350-b633-ab80d83abdbb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_a2379bef-c419-472e-8474-91fe9b4e2ac4" xlink:to="loc_us-gaap_ClassOfStockDomain_84a11624-d870-4350-b633-ab80d83abdbb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_f84f89d1-a650-4c42-8ca1-8d1692d816b1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_84a11624-d870-4350-b633-ab80d83abdbb" xlink:to="loc_us-gaap_EmployeeStockOptionMember_f84f89d1-a650-4c42-8ca1-8d1692d816b1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_cf5da275-511d-4400-9ad4-deb6ee6bc4a6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_630b000e-fd99-4e70-9787-eb79ed229437" xlink:to="loc_us-gaap_PlanNameAxis_cf5da275-511d-4400-9ad4-deb6ee6bc4a6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_cf5da275-511d-4400-9ad4-deb6ee6bc4a6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_cf5da275-511d-4400-9ad4-deb6ee6bc4a6" xlink:to="loc_us-gaap_PlanNameDomain_cf5da275-511d-4400-9ad4-deb6ee6bc4a6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_81081e0a-fac5-4acb-b6f1-8ef2edcb678d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_cf5da275-511d-4400-9ad4-deb6ee6bc4a6" xlink:to="loc_us-gaap_PlanNameDomain_81081e0a-fac5-4acb-b6f1-8ef2edcb678d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_A2017EquityandIncentiveCompensationPlanMember_8db6cd92-cad9-490a-b437-1099d88fd193" xlink:href="trs-20241231.xsd#trs_A2017EquityandIncentiveCompensationPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_81081e0a-fac5-4acb-b6f1-8ef2edcb678d" xlink:to="loc_trs_A2017EquityandIncentiveCompensationPlanMember_8db6cd92-cad9-490a-b437-1099d88fd193" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DirectorRetainerMember_4c1352e8-f508-492b-9c07-9f9cb1104c54" xlink:href="trs-20241231.xsd#trs_DirectorRetainerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_81081e0a-fac5-4acb-b6f1-8ef2edcb678d" xlink:to="loc_trs_DirectorRetainerMember_4c1352e8-f508-492b-9c07-9f9cb1104c54" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_A2011PlanMember_14b95e1c-52d6-44e5-9cfa-290033eb617a" xlink:href="trs-20241231.xsd#trs_A2011PlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_81081e0a-fac5-4acb-b6f1-8ef2edcb678d" xlink:to="loc_trs_A2011PlanMember_14b95e1c-52d6-44e5-9cfa-290033eb617a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_A2006PlanMember_fc850d10-f95e-45aa-8782-34f28851f38c" xlink:href="trs-20241231.xsd#trs_A2006PlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_81081e0a-fac5-4acb-b6f1-8ef2edcb678d" xlink:to="loc_trs_A2006PlanMember_fc850d10-f95e-45aa-8782-34f28851f38c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_A2002PlanMember_267719aa-5875-431e-9f8c-b0a3931714b1" xlink:href="trs-20241231.xsd#trs_A2002PlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_81081e0a-fac5-4acb-b6f1-8ef2edcb678d" xlink:to="loc_trs_A2002PlanMember_267719aa-5875-431e-9f8c-b0a3931714b1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_c3900c9a-dfbc-4a23-82d2-4577340212cd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_630b000e-fd99-4e70-9787-eb79ed229437" xlink:to="loc_us-gaap_AwardTypeAxis_c3900c9a-dfbc-4a23-82d2-4577340212cd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c3900c9a-dfbc-4a23-82d2-4577340212cd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_c3900c9a-dfbc-4a23-82d2-4577340212cd" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c3900c9a-dfbc-4a23-82d2-4577340212cd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_617e0f2f-a26b-4340-ac73-3e6699304ef4" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_c3900c9a-dfbc-4a23-82d2-4577340212cd" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_617e0f2f-a26b-4340-ac73-3e6699304ef4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_f2570bb8-a90c-402b-b76a-6fa40231e551" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_617e0f2f-a26b-4340-ac73-3e6699304ef4" xlink:to="loc_us-gaap_EmployeeStockOptionMember_f2570bb8-a90c-402b-b76a-6fa40231e551" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_df1b24a3-eeb0-4d32-b400-aa9824ad97ad" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_01baa38b-0004-4344-bb43-c9dad7830d54" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_df1b24a3-eeb0-4d32-b400-aa9824ad97ad" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EquityAwardsStockOptionsNarrativeDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EquityAwardsStockOptionsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EquityAwardsStockOptionsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_64ecd44d-9959-49fc-a863-cc79a2116709" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_869ee2c5-599b-433b-a0d4-a1831c880fe7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_64ecd44d-9959-49fc-a863-cc79a2116709" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_869ee2c5-599b-433b-a0d4-a1831c880fe7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_83b6921f-c4d5-4808-acd5-205e57218ed1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_869ee2c5-599b-433b-a0d4-a1831c880fe7" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_83b6921f-c4d5-4808-acd5-205e57218ed1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_83b6921f-c4d5-4808-acd5-205e57218ed1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_83b6921f-c4d5-4808-acd5-205e57218ed1" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_83b6921f-c4d5-4808-acd5-205e57218ed1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_dafa4359-4b0c-46f4-9115-a093857d5905" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_83b6921f-c4d5-4808-acd5-205e57218ed1" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_dafa4359-4b0c-46f4-9115-a093857d5905" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_9d5ce668-fec2-40f2-a983-f0c668780eff" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_dafa4359-4b0c-46f4-9115-a093857d5905" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_9d5ce668-fec2-40f2-a983-f0c668780eff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_a6ae8018-86c8-4810-8e5c-10efff744909" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_869ee2c5-599b-433b-a0d4-a1831c880fe7" xlink:to="loc_us-gaap_AwardTypeAxis_a6ae8018-86c8-4810-8e5c-10efff744909" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a6ae8018-86c8-4810-8e5c-10efff744909_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_a6ae8018-86c8-4810-8e5c-10efff744909" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a6ae8018-86c8-4810-8e5c-10efff744909_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cfea6247-c932-4c53-8fb4-46ce80590504" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_a6ae8018-86c8-4810-8e5c-10efff744909" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cfea6247-c932-4c53-8fb4-46ce80590504" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_a8797dfb-2321-4320-865b-583ca8bb6588" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cfea6247-c932-4c53-8fb4-46ce80590504" xlink:to="loc_us-gaap_EmployeeStockOptionMember_a8797dfb-2321-4320-865b-583ca8bb6588" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_e46e1001-ebc2-4cb5-8f4c-a3e88d14e2ec" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_64ecd44d-9959-49fc-a863-cc79a2116709" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_e46e1001-ebc2-4cb5-8f4c-a3e88d14e2ec" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_bf56f3df-6885-4f2b-bcd7-fdd1943af92a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_64ecd44d-9959-49fc-a863-cc79a2116709" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_bf56f3df-6885-4f2b-bcd7-fdd1943af92a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_84bf5665-065c-4644-b4f7-2dcbb0096475" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_64ecd44d-9959-49fc-a863-cc79a2116709" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_84bf5665-065c-4644-b4f7-2dcbb0096475" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_88720fc5-12a9-4509-ac71-97d81aa93479" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_64ecd44d-9959-49fc-a863-cc79a2116709" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_88720fc5-12a9-4509-ac71-97d81aa93479" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber_cb3f0c86-f090-412b-bf44-9d70851061e9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_64ecd44d-9959-49fc-a863-cc79a2116709" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber_cb3f0c86-f090-412b-bf44-9d70851061e9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_9b9b132d-879e-42a9-9098-8dfa78a99d16" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_64ecd44d-9959-49fc-a863-cc79a2116709" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_9b9b132d-879e-42a9-9098-8dfa78a99d16" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_584f04ff-41ed-4417-b1a4-fc598d119a84" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_64ecd44d-9959-49fc-a863-cc79a2116709" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_584f04ff-41ed-4417-b1a4-fc598d119a84" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_2db67494-9a3a-4cc8-b3a4-015f3c9dfd14" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_64ecd44d-9959-49fc-a863-cc79a2116709" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_2db67494-9a3a-4cc8-b3a4-015f3c9dfd14" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_ef04d300-141a-41ae-903e-414040db9600" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_64ecd44d-9959-49fc-a863-cc79a2116709" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares_ef04d300-141a-41ae-903e-414040db9600" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_bf10ba0c-eebf-4367-b657-0cc586a39ba5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_64ecd44d-9959-49fc-a863-cc79a2116709" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_bf10ba0c-eebf-4367-b657-0cc586a39ba5" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EquityAwardsRestrictedSharesNarrativeDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EquityAwardsRestrictedSharesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EquityAwardsRestrictedSharesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f824e81e-9598-4bec-9e6d-150c7a4a9359" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f824e81e-9598-4bec-9e6d-150c7a4a9359" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_MetricTypeAxis_37229148-0a06-4777-ae9e-9dc1e31f4a13" xlink:href="trs-20241231.xsd#trs_MetricTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f824e81e-9598-4bec-9e6d-150c7a4a9359" xlink:to="loc_trs_MetricTypeAxis_37229148-0a06-4777-ae9e-9dc1e31f4a13" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_MetricTypeDomain_37229148-0a06-4777-ae9e-9dc1e31f4a13_default" xlink:href="trs-20241231.xsd#trs_MetricTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_MetricTypeAxis_37229148-0a06-4777-ae9e-9dc1e31f4a13" xlink:to="loc_trs_MetricTypeDomain_37229148-0a06-4777-ae9e-9dc1e31f4a13_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_MetricTypeDomain_76c1a66f-4c89-4420-9173-a17c67d4421e" xlink:href="trs-20241231.xsd#trs_MetricTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_MetricTypeAxis_37229148-0a06-4777-ae9e-9dc1e31f4a13" xlink:to="loc_trs_MetricTypeDomain_76c1a66f-4c89-4420-9173-a17c67d4421e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_A3YearEpsCagrMetricMember_a2dcd443-abc7-43c2-8e05-c0be86890596" xlink:href="trs-20241231.xsd#trs_A3YearEpsCagrMetricMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_MetricTypeDomain_76c1a66f-4c89-4420-9173-a17c67d4421e" xlink:to="loc_trs_A3YearEpsCagrMetricMember_a2dcd443-abc7-43c2-8e05-c0be86890596" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_TotalshareholderreturnmetricMember_5f463035-6b11-4de7-b876-dcba06217e63" xlink:href="trs-20241231.xsd#trs_TotalshareholderreturnmetricMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_MetricTypeDomain_76c1a66f-4c89-4420-9173-a17c67d4421e" xlink:to="loc_trs_TotalshareholderreturnmetricMember_5f463035-6b11-4de7-b876-dcba06217e63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AveragestockpriceMember_eb8dd70e-7da2-430a-908e-97d1d542104a" xlink:href="trs-20241231.xsd#trs_AveragestockpriceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_MetricTypeDomain_76c1a66f-4c89-4420-9173-a17c67d4421e" xlink:to="loc_trs_AveragestockpriceMember_eb8dd70e-7da2-430a-908e-97d1d542104a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_A3YearEPSRONAMetricMember_c28e3a3e-36a5-475c-9330-5ebfaff17267" xlink:href="trs-20241231.xsd#trs_A3YearEPSRONAMetricMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_MetricTypeDomain_76c1a66f-4c89-4420-9173-a17c67d4421e" xlink:to="loc_trs_A3YearEPSRONAMetricMember_c28e3a3e-36a5-475c-9330-5ebfaff17267" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_294831ee-1c5a-407b-b979-3a53fca54d38" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f824e81e-9598-4bec-9e6d-150c7a4a9359" xlink:to="loc_srt_RangeAxis_294831ee-1c5a-407b-b979-3a53fca54d38" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_294831ee-1c5a-407b-b979-3a53fca54d38_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_294831ee-1c5a-407b-b979-3a53fca54d38" xlink:to="loc_srt_RangeMember_294831ee-1c5a-407b-b979-3a53fca54d38_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_fc61c03c-3e9a-42cb-9921-97d10982c30c" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_294831ee-1c5a-407b-b979-3a53fca54d38" xlink:to="loc_srt_RangeMember_fc61c03c-3e9a-42cb-9921-97d10982c30c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_41a50fac-be4f-4063-8d59-d2712b75cf40" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_fc61c03c-3e9a-42cb-9921-97d10982c30c" xlink:to="loc_srt_MinimumMember_41a50fac-be4f-4063-8d59-d2712b75cf40" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_225d1783-f789-4733-a4c2-57c87c5adfb2" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_fc61c03c-3e9a-42cb-9921-97d10982c30c" xlink:to="loc_srt_MaximumMember_225d1783-f789-4733-a4c2-57c87c5adfb2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_19031c48-4e8c-4354-8a4d-3ac3cfcf7aac" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f824e81e-9598-4bec-9e6d-150c7a4a9359" xlink:to="loc_us-gaap_PlanNameAxis_19031c48-4e8c-4354-8a4d-3ac3cfcf7aac" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_19031c48-4e8c-4354-8a4d-3ac3cfcf7aac_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_19031c48-4e8c-4354-8a4d-3ac3cfcf7aac" xlink:to="loc_us-gaap_PlanNameDomain_19031c48-4e8c-4354-8a4d-3ac3cfcf7aac_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_a4d97237-4adc-4175-9db4-8249e2373d0e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_19031c48-4e8c-4354-8a4d-3ac3cfcf7aac" xlink:to="loc_us-gaap_PlanNameDomain_a4d97237-4adc-4175-9db4-8249e2373d0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Plan1Member_36b5577e-28fe-4d1c-9352-845f4bf01083" xlink:href="trs-20241231.xsd#trs_Plan1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_a4d97237-4adc-4175-9db4-8249e2373d0e" xlink:to="loc_trs_Plan1Member_36b5577e-28fe-4d1c-9352-845f4bf01083" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Plan2Member_1edaeab0-122e-467b-8eb5-0c935f523708" xlink:href="trs-20241231.xsd#trs_Plan2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_a4d97237-4adc-4175-9db4-8249e2373d0e" xlink:to="loc_trs_Plan2Member_1edaeab0-122e-467b-8eb5-0c935f523708" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Plan3Member_5946670a-0f70-4df9-b2a5-797931ae7da8" xlink:href="trs-20241231.xsd#trs_Plan3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_a4d97237-4adc-4175-9db4-8249e2373d0e" xlink:to="loc_trs_Plan3Member_5946670a-0f70-4df9-b2a5-797931ae7da8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Plan4Member_479bb0fb-a7cc-4886-b5c2-d84082e15b68" xlink:href="trs-20241231.xsd#trs_Plan4Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_a4d97237-4adc-4175-9db4-8249e2373d0e" xlink:to="loc_trs_Plan4Member_479bb0fb-a7cc-4886-b5c2-d84082e15b68" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Plan5Member_01625c6a-88ed-4e87-9018-928005ce8686" xlink:href="trs-20241231.xsd#trs_Plan5Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_a4d97237-4adc-4175-9db4-8249e2373d0e" xlink:to="loc_trs_Plan5Member_01625c6a-88ed-4e87-9018-928005ce8686" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Plan6Member_15da37a4-8ba8-402c-a334-d8441256378f" xlink:href="trs-20241231.xsd#trs_Plan6Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_a4d97237-4adc-4175-9db4-8249e2373d0e" xlink:to="loc_trs_Plan6Member_15da37a4-8ba8-402c-a334-d8441256378f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Plan7Member_0a07c6c4-6d92-43b5-b471-49b89f506a70" xlink:href="trs-20241231.xsd#trs_Plan7Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_a4d97237-4adc-4175-9db4-8249e2373d0e" xlink:to="loc_trs_Plan7Member_0a07c6c4-6d92-43b5-b471-49b89f506a70" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Plan8Member_b7efbefc-2264-4f26-bdde-f95470d2f5d1" xlink:href="trs-20241231.xsd#trs_Plan8Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_a4d97237-4adc-4175-9db4-8249e2373d0e" xlink:to="loc_trs_Plan8Member_b7efbefc-2264-4f26-bdde-f95470d2f5d1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Plan9Member_3e1844ff-5314-4855-be5d-95cf37a8ef20" xlink:href="trs-20241231.xsd#trs_Plan9Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_a4d97237-4adc-4175-9db4-8249e2373d0e" xlink:to="loc_trs_Plan9Member_3e1844ff-5314-4855-be5d-95cf37a8ef20" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_61057608-65b7-4f94-8255-3821cc67656e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f824e81e-9598-4bec-9e6d-150c7a4a9359" xlink:to="loc_us-gaap_AwardTypeAxis_61057608-65b7-4f94-8255-3821cc67656e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_61057608-65b7-4f94-8255-3821cc67656e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_61057608-65b7-4f94-8255-3821cc67656e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_61057608-65b7-4f94-8255-3821cc67656e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b689ec2d-3e07-4725-a608-a6c340a6abb8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_61057608-65b7-4f94-8255-3821cc67656e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b689ec2d-3e07-4725-a608-a6c340a6abb8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_01b8b684-ca3d-41ba-8d31-e19e367dfd2b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b689ec2d-3e07-4725-a608-a6c340a6abb8" xlink:to="loc_us-gaap_RestrictedStockMember_01b8b684-ca3d-41ba-8d31-e19e367dfd2b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ServiceBasedRestricedSharesMember_114b0257-64b8-470b-9dcd-6cb4ccb3945d" xlink:href="trs-20241231.xsd#trs_ServiceBasedRestricedSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedStockMember_01b8b684-ca3d-41ba-8d31-e19e367dfd2b" xlink:to="loc_trs_ServiceBasedRestricedSharesMember_114b0257-64b8-470b-9dcd-6cb4ccb3945d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_PerformanceBasedRestricedSharesMember_5cdc577b-a2ba-47ba-8797-e9ca73858121" xlink:href="trs-20241231.xsd#trs_PerformanceBasedRestricedSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedStockMember_01b8b684-ca3d-41ba-8d31-e19e367dfd2b" xlink:to="loc_trs_PerformanceBasedRestricedSharesMember_5cdc577b-a2ba-47ba-8797-e9ca73858121" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_006883af-4edc-43e8-b9bf-0c1712668e0a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b689ec2d-3e07-4725-a608-a6c340a6abb8" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_006883af-4edc-43e8-b9bf-0c1712668e0a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualAxis_76c9a176-1e05-4cd8-8a62-2e5f63b039bd" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f824e81e-9598-4bec-9e6d-150c7a4a9359" xlink:to="loc_srt_TitleOfIndividualAxis_76c9a176-1e05-4cd8-8a62-2e5f63b039bd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_76c9a176-1e05-4cd8-8a62-2e5f63b039bd_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_TitleOfIndividualAxis_76c9a176-1e05-4cd8-8a62-2e5f63b039bd" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_76c9a176-1e05-4cd8-8a62-2e5f63b039bd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_00e2b37d-e253-41e9-b3d4-9f63308a02ed" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_TitleOfIndividualAxis_76c9a176-1e05-4cd8-8a62-2e5f63b039bd" xlink:to="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_00e2b37d-e253-41e9-b3d4-9f63308a02ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_DirectorMember_6a1f50a7-8874-480c-8760-d4ec4243e45a" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_DirectorMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_TitleOfIndividualWithRelationshipToEntityDomain_00e2b37d-e253-41e9-b3d4-9f63308a02ed" xlink:to="loc_srt_DirectorMember_6a1f50a7-8874-480c-8760-d4ec4243e45a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsAxis_fb3c38c6-365a-4afd-942e-eb1168816680" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f824e81e-9598-4bec-9e6d-150c7a4a9359" xlink:to="loc_us-gaap_DividendsAxis_fb3c38c6-365a-4afd-942e-eb1168816680" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsDomain_fb3c38c6-365a-4afd-942e-eb1168816680_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DividendsAxis_fb3c38c6-365a-4afd-942e-eb1168816680" xlink:to="loc_us-gaap_DividendsDomain_fb3c38c6-365a-4afd-942e-eb1168816680_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsDomain_5ce29470-931d-4489-8121-4b8813c8ece1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DividendsAxis_fb3c38c6-365a-4afd-942e-eb1168816680" xlink:to="loc_us-gaap_DividendsDomain_5ce29470-931d-4489-8121-4b8813c8ece1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendDeclaredMember_40535b50-5b56-4bbd-8bb1-246502750905" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendDeclaredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_5ce29470-931d-4489-8121-4b8813c8ece1" xlink:to="loc_us-gaap_DividendDeclaredMember_40535b50-5b56-4bbd-8bb1-246502750905" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DividendEquivalentMember_7d0c5e1a-189e-45e8-96aa-dd5d23a5f64b" xlink:href="trs-20241231.xsd#trs_DividendEquivalentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_5ce29470-931d-4489-8121-4b8813c8ece1" xlink:to="loc_trs_DividendEquivalentMember_7d0c5e1a-189e-45e8-96aa-dd5d23a5f64b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DividendEquivalentAxisAxis_61f04f4c-c8c4-4dc2-b5a5-eb49c3695f34" xlink:href="trs-20241231.xsd#trs_DividendEquivalentAxisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f824e81e-9598-4bec-9e6d-150c7a4a9359" xlink:to="loc_trs_DividendEquivalentAxisAxis_61f04f4c-c8c4-4dc2-b5a5-eb49c3695f34" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DividendEquivalentAxisDomain_61f04f4c-c8c4-4dc2-b5a5-eb49c3695f34_default" xlink:href="trs-20241231.xsd#trs_DividendEquivalentAxisDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_DividendEquivalentAxisAxis_61f04f4c-c8c4-4dc2-b5a5-eb49c3695f34" xlink:to="loc_trs_DividendEquivalentAxisDomain_61f04f4c-c8c4-4dc2-b5a5-eb49c3695f34_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DividendEquivalentAxisDomain_d4bb7966-a5d6-4007-91f5-376d1b4968ce" xlink:href="trs-20241231.xsd#trs_DividendEquivalentAxisDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_DividendEquivalentAxisAxis_61f04f4c-c8c4-4dc2-b5a5-eb49c3695f34" xlink:to="loc_trs_DividendEquivalentAxisDomain_d4bb7966-a5d6-4007-91f5-376d1b4968ce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DividendEquivalentMember_121853ab-c40d-4554-b7e5-03a03e29e272" xlink:href="trs-20241231.xsd#trs_DividendEquivalentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DividendEquivalentAxisDomain_d4bb7966-a5d6-4007-91f5-376d1b4968ce" xlink:to="loc_trs_DividendEquivalentMember_121853ab-c40d-4554-b7e5-03a03e29e272" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_81372c1e-1ae7-4a3d-a851-8ae274dd6d94" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_81372c1e-1ae7-4a3d-a851-8ae274dd6d94" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_4992c84c-a1bd-4b41-a02c-92412f0c6408" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_4992c84c-a1bd-4b41-a02c-92412f0c6408" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_SharebasedCompensationArrangementbySharebasedPaymentAwardPerformancePeriodComplete_6edc0ff2-39eb-4c69-aacf-83e4991af488" xlink:href="trs-20241231.xsd#trs_SharebasedCompensationArrangementbySharebasedPaymentAwardPerformancePeriodComplete"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_trs_SharebasedCompensationArrangementbySharebasedPaymentAwardPerformancePeriodComplete_6edc0ff2-39eb-4c69-aacf-83e4991af488" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardIncentiveCompensationPlanThresholdTargetAwardForGrantingStockAward_4a1b2ddf-d1d8-468b-8d6c-a23c2d99c23f" xlink:href="trs-20241231.xsd#trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardIncentiveCompensationPlanThresholdTargetAwardForGrantingStockAward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardIncentiveCompensationPlanThresholdTargetAwardForGrantingStockAward_4a1b2ddf-d1d8-468b-8d6c-a23c2d99c23f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardCashValueOfIncentivePlan_1c5454aa-adab-40dc-a822-de87a1d1d54c" xlink:href="trs-20241231.xsd#trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardCashValueOfIncentivePlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardCashValueOfIncentivePlan_1c5454aa-adab-40dc-a822-de87a1d1d54c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestricedSharesValueOfIncentivePlan_c1ddbf18-5479-47a1-8dbe-debcda5c29c1" xlink:href="trs-20241231.xsd#trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestricedSharesValueOfIncentivePlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestricedSharesValueOfIncentivePlan_c1ddbf18-5479-47a1-8dbe-debcda5c29c1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_a13d777f-d5c9-4d95-bdf3-dd85f5600fd0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_a13d777f-d5c9-4d95-bdf3-dd85f5600fd0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentageEarnedBasedOnMetricOverPerformancePeriod_ce8c8e7c-1726-4b31-9226-6a6a79d42e66" xlink:href="trs-20241231.xsd#trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentageEarnedBasedOnMetricOverPerformancePeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentageEarnedBasedOnMetricOverPerformancePeriod_ce8c8e7c-1726-4b31-9226-6a6a79d42e66" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentageAttained_fe63e4a7-602e-41a4-954a-1b2646059114" xlink:href="trs-20241231.xsd#trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentageAttained"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentageAttained_fe63e4a7-602e-41a4-954a-1b2646059114" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAmountOfSharesEarnedOfTargetAward_59d6165f-c31d-4a5c-a882-2a5eaa9c4c70" xlink:href="trs-20241231.xsd#trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAmountOfSharesEarnedOfTargetAward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAmountOfSharesEarnedOfTargetAward_59d6165f-c31d-4a5c-a882-2a5eaa9c4c70" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredCompensationArrangementWithIndividualSharesIssued_a6a54d78-14df-4772-b70d-e617fbd6f561" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredCompensationArrangementWithIndividualSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_us-gaap_DeferredCompensationArrangementWithIndividualSharesIssued_a6a54d78-14df-4772-b70d-e617fbd6f561" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceBasedMetricEarningsPerShare_64100172-a02b-44d0-a848-85dec6bcb06b" xlink:href="trs-20241231.xsd#trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceBasedMetricEarningsPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardPerformanceBasedMetricEarningsPerShare_64100172-a02b-44d0-a848-85dec6bcb06b" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_2e4a16ed-f2c1-4e45-a1f3-464b05211d08" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_2e4a16ed-f2c1-4e45-a1f3-464b05211d08" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_15a70539-ee76-4118-b103-75ae53f28310" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_15a70539-ee76-4118-b103-75ae53f28310" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_6f964a37-e926-4ca1-b3d3-36073ace5f0c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_6f964a37-e926-4ca1-b3d3-36073ace5f0c" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_d926d2d6-a317-4141-bb35-a1d0c7a250aa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_d926d2d6-a317-4141-bb35-a1d0c7a250aa" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_ffc6c2fc-4dc5-4ef9-9fc4-c196d57a041c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_ffc6c2fc-4dc5-4ef9-9fc4-c196d57a041c" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPeriodIncreaseDecrease_1fae062f-57b3-4c2e-aa6f-61f3e13b7560" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPeriodIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_fc0f9ce8-6cab-4fab-b001-edaa18b1b08c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsPeriodIncreaseDecrease_1fae062f-57b3-4c2e-aa6f-61f3e13b7560" xlink:type="arc" order="17"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EquityAwardsRestrictedSharesActivityTableDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EquityAwardsRestrictedSharesActivityTableDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EquityAwardsRestrictedSharesActivityTableDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ae1d334d-8f3b-4360-8e92-1d61b658e456" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_3bcbabab-c88c-40da-97c0-b7ea7795e6cb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ae1d334d-8f3b-4360-8e92-1d61b658e456" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_3bcbabab-c88c-40da-97c0-b7ea7795e6cb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_d841eb59-70f0-41cb-a79a-a1869383a5c1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_3bcbabab-c88c-40da-97c0-b7ea7795e6cb" xlink:to="loc_us-gaap_AwardTypeAxis_d841eb59-70f0-41cb-a79a-a1869383a5c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d841eb59-70f0-41cb-a79a-a1869383a5c1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_d841eb59-70f0-41cb-a79a-a1869383a5c1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_d841eb59-70f0-41cb-a79a-a1869383a5c1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_21f44457-c063-4bf9-84b6-98cbad85a9ad" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_d841eb59-70f0-41cb-a79a-a1869383a5c1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_21f44457-c063-4bf9-84b6-98cbad85a9ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_0f549d48-006f-41ff-bc59-1236a0be3240" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_21f44457-c063-4bf9-84b6-98cbad85a9ad" xlink:to="loc_us-gaap_RestrictedStockMember_0f549d48-006f-41ff-bc59-1236a0be3240" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_8759e17f-6d35-49bd-9a28-54f9cdd2748e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ae1d334d-8f3b-4360-8e92-1d61b658e456" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_8759e17f-6d35-49bd-9a28-54f9cdd2748e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_4d7fc3ad-dcb2-4f96-9539-ca35cf176595" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_8759e17f-6d35-49bd-9a28-54f9cdd2748e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_4d7fc3ad-dcb2-4f96-9539-ca35cf176595" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_62982fe8-bf1e-40f4-99cf-cf67f1f31025" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_8759e17f-6d35-49bd-9a28-54f9cdd2748e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_62982fe8-bf1e-40f4-99cf-cf67f1f31025" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_c39db73f-5a8f-4944-8c3f-88af4a8951b3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_8759e17f-6d35-49bd-9a28-54f9cdd2748e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_c39db73f-5a8f-4944-8c3f-88af4a8951b3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_0d51fe84-6567-49f0-aa65-3c31b3fb6aa2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_8759e17f-6d35-49bd-9a28-54f9cdd2748e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_0d51fe84-6567-49f0-aa65-3c31b3fb6aa2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_bd4003dc-4ad0-4ddb-969b-b8d3764092e1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_4ed144d2-5f01-412a-86c1-d5264e9737b7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ae1d334d-8f3b-4360-8e92-1d61b658e456" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_4ed144d2-5f01-412a-86c1-d5264e9737b7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_87d86cd9-1d6f-4191-b4c7-1ba4cbe04765" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_4ed144d2-5f01-412a-86c1-d5264e9737b7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_87d86cd9-1d6f-4191-b4c7-1ba4cbe04765" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_18aff73d-14e4-4c67-adfd-c0d74939acc7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_4ed144d2-5f01-412a-86c1-d5264e9737b7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_18aff73d-14e4-4c67-adfd-c0d74939acc7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_10719ff9-4b91-4b74-b4dd-29da45396738" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_4ed144d2-5f01-412a-86c1-d5264e9737b7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_10719ff9-4b91-4b74-b4dd-29da45396738" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_d262b0d6-2885-4165-9d47-8100fffd7840" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_4ed144d2-5f01-412a-86c1-d5264e9737b7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_d262b0d6-2885-4165-9d47-8100fffd7840" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_7ea94f89-2de9-4ab7-aa50-6afa68b0e693" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_38f54a03-a0e3-4c40-a0d3-1b07eb5dc001" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ae1d334d-8f3b-4360-8e92-1d61b658e456" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_38f54a03-a0e3-4c40-a0d3-1b07eb5dc001" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_975fae95-d674-4ad9-a642-ea82837f10ef" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_38f54a03-a0e3-4c40-a0d3-1b07eb5dc001" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_975fae95-d674-4ad9-a642-ea82837f10ef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedIntrinsicValue_de5e4026-9c56-4fcb-865c-bd29b4d445fd" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedIntrinsicValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_38f54a03-a0e3-4c40-a0d3-1b07eb5dc001" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedIntrinsicValue_de5e4026-9c56-4fcb-865c-bd29b4d445fd" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EarningsperShareEarningsperShareDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EarningsperShareEarningsperShareDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EarningsperShareEarningsperShareDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicLineItems_1db07fd5-0c93-4fd7-810e-a6c2e3bd1324" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EarningsPerShareBasicLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_c439653c-1ed1-4c67-af1a-2f47922bb166" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_1db07fd5-0c93-4fd7-810e-a6c2e3bd1324" xlink:to="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_c439653c-1ed1-4c67-af1a-2f47922bb166" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_1b7fb0c6-d071-4a93-a944-3ecaca1e8192" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEarningsPerShareBasicByCommonClassTable_c439653c-1ed1-4c67-af1a-2f47922bb166" xlink:to="loc_us-gaap_AwardTypeAxis_1b7fb0c6-d071-4a93-a944-3ecaca1e8192" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1b7fb0c6-d071-4a93-a944-3ecaca1e8192_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_1b7fb0c6-d071-4a93-a944-3ecaca1e8192" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1b7fb0c6-d071-4a93-a944-3ecaca1e8192_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c26b457f-657f-40cb-bfa3-e6c91c30f317" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_1b7fb0c6-d071-4a93-a944-3ecaca1e8192" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c26b457f-657f-40cb-bfa3-e6c91c30f317" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_9eede959-4451-4648-9562-641ab805ab4d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c26b457f-657f-40cb-bfa3-e6c91c30f317" xlink:to="loc_us-gaap_RestrictedStockMember_9eede959-4451-4648-9562-641ab805ab4d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_99fd32a2-430b-476a-b188-54aaedb42a97" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c26b457f-657f-40cb-bfa3-e6c91c30f317" xlink:to="loc_us-gaap_EmployeeStockOptionMember_99fd32a2-430b-476a-b188-54aaedb42a97" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_9fbfe73b-4ad0-485c-bc01-973c3f65d1b8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_1db07fd5-0c93-4fd7-810e-a6c2e3bd1324" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_9fbfe73b-4ad0-485c-bc01-973c3f65d1b8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_d44bd637-6d9f-4605-82e6-97ff080a2d63" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_1db07fd5-0c93-4fd7-810e-a6c2e3bd1324" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_d44bd637-6d9f-4605-82e6-97ff080a2d63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_286b522c-42c7-40bf-88d0-ecf1a3d160b9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicLineItems_1db07fd5-0c93-4fd7-810e-a6c2e3bd1324" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_286b522c-42c7-40bf-88d0-ecf1a3d160b9" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/EarningsperSharePurchaseofCommonStockDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#EarningsperSharePurchaseofCommonStockDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EarningsperSharePurchaseofCommonStockDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_cf243f85-da55-4a92-b8bb-920d8e3364a0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_357ab713-2e01-416e-87ae-94adc54cca09" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_cf243f85-da55-4a92-b8bb-920d8e3364a0" xlink:to="loc_us-gaap_StatementTable_357ab713-2e01-416e-87ae-94adc54cca09" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramAxis_6c77b3c3-c64d-45da-8ff3-14479e82927e" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ShareRepurchaseProgramAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_357ab713-2e01-416e-87ae-94adc54cca09" xlink:to="loc_srt_ShareRepurchaseProgramAxis_6c77b3c3-c64d-45da-8ff3-14479e82927e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_6c77b3c3-c64d-45da-8ff3-14479e82927e_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ShareRepurchaseProgramAxis_6c77b3c3-c64d-45da-8ff3-14479e82927e" xlink:to="loc_srt_ShareRepurchaseProgramDomain_6c77b3c3-c64d-45da-8ff3-14479e82927e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ShareRepurchaseProgramDomain_3689974c-6b40-43b9-a7a5-31bc959ad34c" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ShareRepurchaseProgramDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ShareRepurchaseProgramAxis_6c77b3c3-c64d-45da-8ff3-14479e82927e" xlink:to="loc_srt_ShareRepurchaseProgramDomain_3689974c-6b40-43b9-a7a5-31bc959ad34c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_A10b51sharerepurchaseprogramMember_e2239c03-3faa-4cb9-a30a-33dcb1fbdc29" xlink:href="trs-20241231.xsd#trs_A10b51sharerepurchaseprogramMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ShareRepurchaseProgramDomain_3689974c-6b40-43b9-a7a5-31bc959ad34c" xlink:to="loc_trs_A10b51sharerepurchaseprogramMember_e2239c03-3faa-4cb9-a30a-33dcb1fbdc29" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_54988528-8d18-4486-ada0-ee781e66cb19" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_cf243f85-da55-4a92-b8bb-920d8e3364a0" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_54988528-8d18-4486-ada0-ee781e66cb19" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_542a4a4d-8144-4dab-aa91-adf4b1830f88" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_cf243f85-da55-4a92-b8bb-920d8e3364a0" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodShares_542a4a4d-8144-4dab-aa91-adf4b1830f88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_df2da85e-7a4c-404a-9c69-e3708a6b231d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchasedAndRetiredDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_cf243f85-da55-4a92-b8bb-920d8e3364a0" xlink:to="loc_us-gaap_StockRepurchasedAndRetiredDuringPeriodValue_df2da85e-7a4c-404a-9c69-e3708a6b231d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_7f045b82-97ce-42ab-b01a-a15516bd5e00" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_cf243f85-da55-4a92-b8bb-920d8e3364a0" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_7f045b82-97ce-42ab-b01a-a15516bd5e00" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/OtherComprehensiveIncomeDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#OtherComprehensiveIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/OtherComprehensiveIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_29411472-6805-45a5-8a86-b46e2963f5ea" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_e793e8db-60eb-4587-a7ca-21f9cf059f1e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_29411472-6805-45a5-8a86-b46e2963f5ea" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_e793e8db-60eb-4587-a7ca-21f9cf059f1e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_7a0416ce-f6cc-4d6a-9f46-c51e8d72a795" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_e793e8db-60eb-4587-a7ca-21f9cf059f1e" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_7a0416ce-f6cc-4d6a-9f46-c51e8d72a795" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_7a0416ce-f6cc-4d6a-9f46-c51e8d72a795_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_7a0416ce-f6cc-4d6a-9f46-c51e8d72a795" xlink:to="loc_us-gaap_EquityComponentDomain_7a0416ce-f6cc-4d6a-9f46-c51e8d72a795_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_4aaa8bbf-c7ca-4808-94e3-ef59dadcd5aa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_7a0416ce-f6cc-4d6a-9f46-c51e8d72a795" xlink:to="loc_us-gaap_EquityComponentDomain_4aaa8bbf-c7ca-4808-94e3-ef59dadcd5aa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_20e363de-e656-46d2-b070-2c89c385c111" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_4aaa8bbf-c7ca-4808-94e3-ef59dadcd5aa" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_20e363de-e656-46d2-b070-2c89c385c111" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember_d45893bc-6e99-4e26-b8d0-4b09b8dcb7bf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_4aaa8bbf-c7ca-4808-94e3-ef59dadcd5aa" xlink:to="loc_us-gaap_AccumulatedNetGainLossFromDesignatedOrQualifyingCashFlowHedgesMember_d45893bc-6e99-4e26-b8d0-4b09b8dcb7bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_7b38c903-52e5-4779-9caf-762005e53ad6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_4aaa8bbf-c7ca-4808-94e3-ef59dadcd5aa" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_7b38c903-52e5-4779-9caf-762005e53ad6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_96fb7129-efef-43c9-9870-df5d16a5122a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_4aaa8bbf-c7ca-4808-94e3-ef59dadcd5aa" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_96fb7129-efef-43c9-9870-df5d16a5122a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AccumulatedNetGainLossfromHedgesAttributabletoParentMember_dd32ad26-98f1-494c-b61a-bc78e0324dbc" xlink:href="trs-20241231.xsd#trs_AccumulatedNetGainLossfromHedgesAttributabletoParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_4aaa8bbf-c7ca-4808-94e3-ef59dadcd5aa" xlink:to="loc_trs_AccumulatedNetGainLossfromHedgesAttributabletoParentMember_dd32ad26-98f1-494c-b61a-bc78e0324dbc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_894dff38-38b8-4ca3-a4ad-42cb09d9ee43" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_e793e8db-60eb-4587-a7ca-21f9cf059f1e" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_894dff38-38b8-4ca3-a4ad-42cb09d9ee43" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_894dff38-38b8-4ca3-a4ad-42cb09d9ee43_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_894dff38-38b8-4ca3-a4ad-42cb09d9ee43" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_894dff38-38b8-4ca3-a4ad-42cb09d9ee43_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_a2ffe100-2073-433e-a3dc-fa5f66f9e33c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_894dff38-38b8-4ca3-a4ad-42cb09d9ee43" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_a2ffe100-2073-433e-a3dc-fa5f66f9e33c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CrossCurrencyInterestRateContractMember_0c1236b8-f035-4209-b76b-f97a54357719" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CrossCurrencyInterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_a2ffe100-2073-433e-a3dc-fa5f66f9e33c" xlink:to="loc_us-gaap_CrossCurrencyInterestRateContractMember_0c1236b8-f035-4209-b76b-f97a54357719" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AccumulatedOtherComprehensiveIncomeNetofTaxRollForward_ca76bbef-6db8-4b77-bb24-96d6363b6a9b" xlink:href="trs-20241231.xsd#trs_AccumulatedOtherComprehensiveIncomeNetofTaxRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_29411472-6805-45a5-8a86-b46e2963f5ea" xlink:to="loc_trs_AccumulatedOtherComprehensiveIncomeNetofTaxRollForward_ca76bbef-6db8-4b77-bb24-96d6363b6a9b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_d99b8887-adde-4ca2-a9d1-df87694855da" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_AccumulatedOtherComprehensiveIncomeNetofTaxRollForward_ca76bbef-6db8-4b77-bb24-96d6363b6a9b" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_d99b8887-adde-4ca2-a9d1-df87694855da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_a6cc1433-286c-4f74-af85-a800d7fe4b5d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_AccumulatedOtherComprehensiveIncomeNetofTaxRollForward_ca76bbef-6db8-4b77-bb24-96d6363b6a9b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_a6cc1433-286c-4f74-af85-a800d7fe4b5d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_1d0745eb-af85-4a8d-b33f-2f7cc9b2c6e7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_AccumulatedOtherComprehensiveIncomeNetofTaxRollForward_ca76bbef-6db8-4b77-bb24-96d6363b6a9b" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_1d0745eb-af85-4a8d-b33f-2f7cc9b2c6e7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_091ed6b1-0b66-40aa-a3b9-bbbe04758aac" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_AccumulatedOtherComprehensiveIncomeNetofTaxRollForward_ca76bbef-6db8-4b77-bb24-96d6363b6a9b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_091ed6b1-0b66-40aa-a3b9-bbbe04758aac" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Reclassificationofstrandedtaxeffects_01b165f1-50e4-4f04-b877-834b44ec8d43" xlink:href="trs-20241231.xsd#trs_Reclassificationofstrandedtaxeffects"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_AccumulatedOtherComprehensiveIncomeNetofTaxRollForward_ca76bbef-6db8-4b77-bb24-96d6363b6a9b" xlink:to="loc_trs_Reclassificationofstrandedtaxeffects_01b165f1-50e4-4f04-b877-834b44ec8d43" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_453d1cc6-16d2-4508-9f27-f74864003692" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossTax_43721659-c2b2-4c7d-81e2-c063bc7ef001" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherComprehensiveIncomeLossTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_29411472-6805-45a5-8a86-b46e2963f5ea" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossTax_43721659-c2b2-4c7d-81e2-c063bc7ef001" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/SegmentInformationDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#SegmentInformationDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SegmentInformationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_859a98bd-1283-4f16-9252-de7396fb04b1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_859a98bd-1283-4f16-9252-de7396fb04b1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_dcefa1d0-cdf2-4b01-8791-613504ac8a95" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementOperatingActivitiesSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_859a98bd-1283-4f16-9252-de7396fb04b1" xlink:to="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_dcefa1d0-cdf2-4b01-8791-613504ac8a95" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_dcefa1d0-cdf2-4b01-8791-613504ac8a95_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentOperatingActivitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_dcefa1d0-cdf2-4b01-8791-613504ac8a95" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_dcefa1d0-cdf2-4b01-8791-613504ac8a95_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_d83c168f-3cd2-4603-bf55-feab997cebde" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentOperatingActivitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_dcefa1d0-cdf2-4b01-8791-613504ac8a95" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_d83c168f-3cd2-4603-bf55-feab997cebde" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentContinuingOperationsMember_b3585881-ad91-499b-89d4-3da2a4a49341" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentContinuingOperationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentOperatingActivitiesDomain_d83c168f-3cd2-4603-bf55-feab997cebde" xlink:to="loc_us-gaap_SegmentContinuingOperationsMember_b3585881-ad91-499b-89d4-3da2a4a49341" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDiscontinuedOperationsMember_e59cdbbb-1071-4edc-a37e-96a2554ec874" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDiscontinuedOperationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentOperatingActivitiesDomain_d83c168f-3cd2-4603-bf55-feab997cebde" xlink:to="loc_us-gaap_SegmentDiscontinuedOperationsMember_e59cdbbb-1071-4edc-a37e-96a2554ec874" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_c1cb1cc8-afeb-4d6b-9974-4efe0578d2b2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_859a98bd-1283-4f16-9252-de7396fb04b1" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_c1cb1cc8-afeb-4d6b-9974-4efe0578d2b2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_c1cb1cc8-afeb-4d6b-9974-4efe0578d2b2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_c1cb1cc8-afeb-4d6b-9974-4efe0578d2b2" xlink:to="loc_us-gaap_SegmentDomain_c1cb1cc8-afeb-4d6b-9974-4efe0578d2b2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_42cabb0f-d99d-44f8-9d08-a1583388d38e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_c1cb1cc8-afeb-4d6b-9974-4efe0578d2b2" xlink:to="loc_us-gaap_SegmentDomain_42cabb0f-d99d-44f8-9d08-a1583388d38e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_PackagingReportableSegmentMember_3f20f9fc-0838-4935-aad4-6d7170d8b970" xlink:href="trs-20241231.xsd#trs_PackagingReportableSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_42cabb0f-d99d-44f8-9d08-a1583388d38e" xlink:to="loc_trs_PackagingReportableSegmentMember_3f20f9fc-0838-4935-aad4-6d7170d8b970" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AerospaceReportableSegmentMember_ad0341e9-41ae-4029-b28d-e6dfbaf6d794" xlink:href="trs-20241231.xsd#trs_AerospaceReportableSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_42cabb0f-d99d-44f8-9d08-a1583388d38e" xlink:to="loc_trs_AerospaceReportableSegmentMember_ad0341e9-41ae-4029-b28d-e6dfbaf6d794" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_SpecialtyProductsReportableSegmentMember_d66bf2cc-babe-4bf8-a769-203d9e4e08e1" xlink:href="trs-20241231.xsd#trs_SpecialtyProductsReportableSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_42cabb0f-d99d-44f8-9d08-a1583388d38e" xlink:to="loc_trs_SpecialtyProductsReportableSegmentMember_d66bf2cc-babe-4bf8-a769-203d9e4e08e1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateMember_2529076f-03d4-4a3c-807b-d439cf5f470d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_CorporateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_42cabb0f-d99d-44f8-9d08-a1583388d38e" xlink:to="loc_us-gaap_CorporateMember_2529076f-03d4-4a3c-807b-d439cf5f470d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReportableSegmentAggregationBeforeOtherOperatingSegmentMember_67703ffd-bb04-4ab7-9702-82788d28175e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ReportableSegmentAggregationBeforeOtherOperatingSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_42cabb0f-d99d-44f8-9d08-a1583388d38e" xlink:to="loc_us-gaap_ReportableSegmentAggregationBeforeOtherOperatingSegmentMember_67703ffd-bb04-4ab7-9702-82788d28175e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c8607158-478b-4f28-ba43-89ff26487a25" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_859a98bd-1283-4f16-9252-de7396fb04b1" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c8607158-478b-4f28-ba43-89ff26487a25" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c8607158-478b-4f28-ba43-89ff26487a25_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c8607158-478b-4f28-ba43-89ff26487a25" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_c8607158-478b-4f28-ba43-89ff26487a25_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_cf865b57-9f55-4c11-ab96-a94dc3943c38" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_c8607158-478b-4f28-ba43-89ff26487a25" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_cf865b57-9f55-4c11-ab96-a94dc3943c38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandAndLandImprovementsMember_2f2c6c86-f00c-4962-acf3-45d0d8bfc740" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LandAndLandImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_cf865b57-9f55-4c11-ab96-a94dc3943c38" xlink:to="loc_us-gaap_LandAndLandImprovementsMember_2f2c6c86-f00c-4962-acf3-45d0d8bfc740" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NatureOfExpenseAxis_bae7baf9-70a0-4c4b-bd39-59b8d7b7b83a" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NatureOfExpenseAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_859a98bd-1283-4f16-9252-de7396fb04b1" xlink:to="loc_us-gaap_NatureOfExpenseAxis_bae7baf9-70a0-4c4b-bd39-59b8d7b7b83a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterimPeriodCostsNotAllocableDomain_bae7baf9-70a0-4c4b-bd39-59b8d7b7b83a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterimPeriodCostsNotAllocableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_NatureOfExpenseAxis_bae7baf9-70a0-4c4b-bd39-59b8d7b7b83a" xlink:to="loc_us-gaap_InterimPeriodCostsNotAllocableDomain_bae7baf9-70a0-4c4b-bd39-59b8d7b7b83a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterimPeriodCostsNotAllocableDomain_c419a209-0d32-4bba-a083-2b620b609a60" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterimPeriodCostsNotAllocableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_NatureOfExpenseAxis_bae7baf9-70a0-4c4b-bd39-59b8d7b7b83a" xlink:to="loc_us-gaap_InterimPeriodCostsNotAllocableDomain_c419a209-0d32-4bba-a083-2b620b609a60" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_ac2bd162-b635-420e-a638-b3185fba78c0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_859a98bd-1283-4f16-9252-de7396fb04b1" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_ac2bd162-b635-420e-a638-b3185fba78c0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_ac2bd162-b635-420e-a638-b3185fba78c0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_ac2bd162-b635-420e-a638-b3185fba78c0" xlink:to="loc_us-gaap_LossContingencyNatureDomain_ac2bd162-b635-420e-a638-b3185fba78c0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_dd20f747-fda6-4081-ac6d-87068dfb6707" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_ac2bd162-b635-420e-a638-b3185fba78c0" xlink:to="loc_us-gaap_LossContingencyNatureDomain_dd20f747-fda6-4081-ac6d-87068dfb6707" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AsbestosIssueMember_c9023fc3-554e-4be2-922a-46123d251213" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AsbestosIssueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_dd20f747-fda6-4081-ac6d-87068dfb6707" xlink:to="loc_us-gaap_AsbestosIssueMember_c9023fc3-554e-4be2-922a-46123d251213" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EnvironmentalIssueMember_5fffaba4-4db9-47ea-8bb3-5152b72627e6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_EnvironmentalIssueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_dd20f747-fda6-4081-ac6d-87068dfb6707" xlink:to="loc_us-gaap_EnvironmentalIssueMember_5fffaba4-4db9-47ea-8bb3-5152b72627e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_65d63f63-e755-44d4-bf56-67ef5f816311" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_Revenues_65d63f63-e755-44d4-bf56-67ef5f816311" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AdjustedCostOfSales_c71d44f8-1188-45c8-b305-531f10ea5ccf" xlink:href="trs-20241231.xsd#trs_AdjustedCostOfSales"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_trs_AdjustedCostOfSales_c71d44f8-1188-45c8-b305-531f10ea5ccf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_AdjustedSellingGeneralAndAdministrativeExpenses_649b8551-6c4d-4937-8e49-61a669027bae" xlink:href="trs-20241231.xsd#trs_AdjustedSellingGeneralAndAdministrativeExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_trs_AdjustedSellingGeneralAndAdministrativeExpenses_649b8551-6c4d-4937-8e49-61a669027bae" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherItemAmount_a44d4e01-ab19-42b4-92d4-23c234e634fb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingOtherItemAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_SegmentReportingOtherItemAmount_a44d4e01-ab19-42b4-92d4-23c234e634fb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_SegmentAdjustedOperatingProfit_ab001be8-4310-472f-b98c-7c8f0af33827" xlink:href="trs-20241231.xsd#trs_SegmentAdjustedOperatingProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_trs_SegmentAdjustedOperatingProfit_ab001be8-4310-472f-b98c-7c8f0af33827" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_ec7c6730-588a-4f92-908f-d8a3d14a04c0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_OperatingIncomeLoss_ec7c6730-588a-4f92-908f-d8a3d14a04c0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_ThirdPartyAndOtherCostsIncurredRelatedToStrike_3830259e-35de-45e1-9f9e-5d150646e1d1" xlink:href="trs-20241231.xsd#trs_ThirdPartyAndOtherCostsIncurredRelatedToStrike"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_trs_ThirdPartyAndOtherCostsIncurredRelatedToStrike_3830259e-35de-45e1-9f9e-5d150646e1d1" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_RealignmentAndSeveranceCosts_cc35258c-4a7e-4061-a301-1437607ce286" xlink:href="trs-20241231.xsd#trs_RealignmentAndSeveranceCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_trs_RealignmentAndSeveranceCosts_cc35258c-4a7e-4061-a301-1437607ce286" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_PurchaseAccountingCosts_d12ff40c-8362-404a-bb44-bfd5a771e874" xlink:href="trs-20241231.xsd#trs_PurchaseAccountingCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_trs_PurchaseAccountingCosts_d12ff40c-8362-404a-bb44-bfd5a771e874" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireProductiveAssets_66d544fa-b756-4d7c-8f43-e4b2d632bb9d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsToAcquireProductiveAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_PaymentsToAcquireProductiveAssets_66d544fa-b756-4d7c-8f43-e4b2d632bb9d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_97ec6b9a-eb84-4e7b-82c7-d7039264de82" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_97ec6b9a-eb84-4e7b-82c7-d7039264de82" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_fd781331-d6b6-445e-8fc5-cf22230b8142" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_Assets_fd781331-d6b6-445e-8fc5-cf22230b8142" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnDispositionOfAssets_20eb4929-6c1f-497a-8499-ec963bc7a6c2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GainLossOnDispositionOfAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_GainLossOnDispositionOfAssets_20eb4929-6c1f-497a-8499-ec963bc7a6c2" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_4ef8d338-22b1-4a6d-8416-b9429533c2f8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_4ef8d338-22b1-4a6d-8416-b9429533c2f8" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_58c58b76-162e-4336-b846-6f93a494c8ac" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_InterestExpenseNonoperating_58c58b76-162e-4336-b846-6f93a494c8ac" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAndIntangibleAssetImpairment_d461a045-5539-431c-8a02-a50a473beb9c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_GoodwillAndIntangibleAssetImpairment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_GoodwillAndIntangibleAssetImpairment_d461a045-5539-431c-8a02-a50a473beb9c" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_MergersAcquisitionsDiligenceAndTransactionCosts_af194f69-9041-46e3-b63a-677b66be902c" xlink:href="trs-20241231.xsd#trs_MergersAcquisitionsDiligenceAndTransactionCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_trs_MergersAcquisitionsDiligenceAndTransactionCosts_af194f69-9041-46e3-b63a-677b66be902c" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_2ffcd6c4-4dd9-4ac2-a64d-bafb9ba838ba" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_2ffcd6c4-4dd9-4ac2-a64d-bafb9ba838ba" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_c0c82248-cf52-46e0-8dc4-17e95620e212" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_c0c82248-cf52-46e0-8dc4-17e95620e212" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestructuringReserveAcceleratedDepreciation_cf3c38ee-ab70-4141-8975-e75d7914e3cb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RestructuringReserveAcceleratedDepreciation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_RestructuringReserveAcceleratedDepreciation_cf3c38ee-ab70-4141-8975-e75d7914e3cb" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonrecurringIncomeExpense_c80f0e8b-13d4-4450-87be-3a19fb030fc0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherNonrecurringIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_OtherNonrecurringIncomeExpense_c80f0e8b-13d4-4450-87be-3a19fb030fc0" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsGrossPeriodIncreaseDecrease_9cf37554-c1aa-4753-862e-9183ab283c42" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsGrossPeriodIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsGrossPeriodIncreaseDecrease_9cf37554-c1aa-4753-862e-9183ab283c42" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_SystemImplementationCosts_502ec391-e3dd-4c51-9de1-6b140cd44d58" xlink:href="trs-20241231.xsd#trs_SystemImplementationCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_trs_SystemImplementationCosts_502ec391-e3dd-4c51-9de1-6b140cd44d58" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingCodmIndividualTitleAndPositionOrGroupOrCommitteeNameExtensibleEnumeration_be65421d-a401-4374-84ec-272c5094eed0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SegmentReportingCodmIndividualTitleAndPositionOrGroupOrCommitteeNameExtensibleEnumeration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_77522912-b328-47e8-805f-8d9b24115875" xlink:to="loc_us-gaap_SegmentReportingCodmIndividualTitleAndPositionOrGroupOrCommitteeNameExtensibleEnumeration_be65421d-a401-4374-84ec-272c5094eed0" xlink:type="arc" order="23"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/SegmentInformationRevenuesandOperatingNetAssetsbyGeographicalAreasDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#SegmentInformationRevenuesandOperatingNetAssetsbyGeographicalAreasDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SegmentInformationRevenuesandOperatingNetAssetsbyGeographicalAreasDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_f2c59369-0188-4b43-8f39-6162ebb5ced1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_82967a13-2554-44a2-a9bc-b13496df20c7" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_f2c59369-0188-4b43-8f39-6162ebb5ced1" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_82967a13-2554-44a2-a9bc-b13496df20c7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_4a85151a-d100-45a8-9dcf-46e3bea0569b" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_82967a13-2554-44a2-a9bc-b13496df20c7" xlink:to="loc_srt_StatementGeographicalAxis_4a85151a-d100-45a8-9dcf-46e3bea0569b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_4a85151a-d100-45a8-9dcf-46e3bea0569b_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_4a85151a-d100-45a8-9dcf-46e3bea0569b" xlink:to="loc_srt_SegmentGeographicalDomain_4a85151a-d100-45a8-9dcf-46e3bea0569b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_2306967b-b8ed-49c4-8a0f-f7ad43aea7e0" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_4a85151a-d100-45a8-9dcf-46e3bea0569b" xlink:to="loc_srt_SegmentGeographicalDomain_2306967b-b8ed-49c4-8a0f-f7ad43aea7e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EuropeMember_9a36947f-d60d-4d92-ac7e-385435d56340" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_EuropeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_2306967b-b8ed-49c4-8a0f-f7ad43aea7e0" xlink:to="loc_srt_EuropeMember_9a36947f-d60d-4d92-ac7e-385435d56340" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_AsiaPacificMember_f91c50d6-1793-4fea-82c9-210ac6022c2d" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_AsiaPacificMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_2306967b-b8ed-49c4-8a0f-f7ad43aea7e0" xlink:to="loc_srt_AsiaPacificMember_f91c50d6-1793-4fea-82c9-210ac6022c2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_OtherAmericasMember_92e0ec48-bb39-4e33-8fb0-70b692614f1e" xlink:href="trs-20241231.xsd#trs_OtherAmericasMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_2306967b-b8ed-49c4-8a0f-f7ad43aea7e0" xlink:to="loc_trs_OtherAmericasMember_92e0ec48-bb39-4e33-8fb0-70b692614f1e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_6ed6618f-512f-4ed1-9f1d-d6cec3782055" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_2306967b-b8ed-49c4-8a0f-f7ad43aea7e0" xlink:to="loc_us-gaap_NonUsMember_6ed6618f-512f-4ed1-9f1d-d6cec3782055" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_0d3b36de-4970-4f32-93df-5ce8f51ab57e" xlink:href="https://xbrl.sec.gov/country/2024/country-2024.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_2306967b-b8ed-49c4-8a0f-f7ad43aea7e0" xlink:to="loc_country_US_0d3b36de-4970-4f32-93df-5ce8f51ab57e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_6f1fb2e7-a3d8-46b8-80fe-8409a7e47186" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_f2c59369-0188-4b43-8f39-6162ebb5ced1" xlink:to="loc_us-gaap_Revenues_6f1fb2e7-a3d8-46b8-80fe-8409a7e47186" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncurrentAssets_c0e6fce3-c260-4416-9931-385c75a10b16" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_NoncurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_f2c59369-0188-4b43-8f39-6162ebb5ced1" xlink:to="loc_us-gaap_NoncurrentAssets_c0e6fce3-c260-4416-9931-385c75a10b16" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/IncomeTaxesComponentsofDeferredTaxesDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#IncomeTaxesComponentsofDeferredTaxesDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/IncomeTaxesComponentsofDeferredTaxesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceLineItems_fa7aece6-beaf-4d9b-b2ee-0896e5e7075f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowanceLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceTable_70decbc1-72ba-45f6-be32-b6423bbdf837" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowanceTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ValuationAllowanceLineItems_fa7aece6-beaf-4d9b-b2ee-0896e5e7075f" xlink:to="loc_us-gaap_ValuationAllowanceTable_70decbc1-72ba-45f6-be32-b6423bbdf837" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_515815bf-55f9-406c-80ee-e41cbc4f862d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ValuationAllowanceTable_70decbc1-72ba-45f6-be32-b6423bbdf837" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_515815bf-55f9-406c-80ee-e41cbc4f862d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_515815bf-55f9-406c-80ee-e41cbc4f862d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_515815bf-55f9-406c-80ee-e41cbc4f862d" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_515815bf-55f9-406c-80ee-e41cbc4f862d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_3459f0a5-f20c-4040-b9f3-ac77cf5abf26" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_515815bf-55f9-406c-80ee-e41cbc4f862d" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_3459f0a5-f20c-4040-b9f3-ac77cf5abf26" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticCountryMember_5e70d34b-8c2a-4497-bafb-a6436099ae8d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DomesticCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_3459f0a5-f20c-4040-b9f3-ac77cf5abf26" xlink:to="loc_us-gaap_DomesticCountryMember_5e70d34b-8c2a-4497-bafb-a6436099ae8d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_DeferredTaxAssetsResearchAndExperimentation_94740faa-e1b8-494a-9910-467e00f4dadf" xlink:href="trs-20241231.xsd#trs_DeferredTaxAssetsResearchAndExperimentation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowanceLineItems_fa7aece6-beaf-4d9b-b2ee-0896e5e7075f" xlink:to="loc_trs_DeferredTaxAssetsResearchAndExperimentation_94740faa-e1b8-494a-9910-467e00f4dadf" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/IncomeTaxesIncomeTaxExpenseReconciliationDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#IncomeTaxesIncomeTaxExpenseReconciliationDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/IncomeTaxesIncomeTaxExpenseReconciliationDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceLineItems_5b135639-3830-4d91-bc87-422e5c93a952" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowanceLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceTable_4abb7427-5db7-4dc2-8c9e-a75e2e90d17c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowanceTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ValuationAllowanceLineItems_5b135639-3830-4d91-bc87-422e5c93a952" xlink:to="loc_us-gaap_ValuationAllowanceTable_4abb7427-5db7-4dc2-8c9e-a75e2e90d17c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_dfff6361-d8c8-4b5b-a593-3d080bd390dc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ValuationAllowanceTable_4abb7427-5db7-4dc2-8c9e-a75e2e90d17c" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_dfff6361-d8c8-4b5b-a593-3d080bd390dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_dfff6361-d8c8-4b5b-a593-3d080bd390dc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_dfff6361-d8c8-4b5b-a593-3d080bd390dc" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_dfff6361-d8c8-4b5b-a593-3d080bd390dc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_10604a01-dd42-4391-8194-14c8bb4da02f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_dfff6361-d8c8-4b5b-a593-3d080bd390dc" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_10604a01-dd42-4391-8194-14c8bb4da02f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCountryMember_f404c402-5e62-4378-9376-f40de7b261ef" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_10604a01-dd42-4391-8194-14c8bb4da02f" xlink:to="loc_us-gaap_ForeignCountryMember_f404c402-5e62-4378-9376-f40de7b261ef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceByDeferredTaxAssetAxis_3f4a9cf4-ce98-4b68-ad0f-ee6ba837a160" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowanceByDeferredTaxAssetAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ValuationAllowanceTable_4abb7427-5db7-4dc2-8c9e-a75e2e90d17c" xlink:to="loc_us-gaap_ValuationAllowanceByDeferredTaxAssetAxis_3f4a9cf4-ce98-4b68-ad0f-ee6ba837a160" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetDomain_3f4a9cf4-ce98-4b68-ad0f-ee6ba837a160_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredTaxAssetDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationAllowanceByDeferredTaxAssetAxis_3f4a9cf4-ce98-4b68-ad0f-ee6ba837a160" xlink:to="loc_us-gaap_DeferredTaxAssetDomain_3f4a9cf4-ce98-4b68-ad0f-ee6ba837a160_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetDomain_3f35239a-e3aa-4e23-9e1b-0de48310f304" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredTaxAssetDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationAllowanceByDeferredTaxAssetAxis_3f4a9cf4-ce98-4b68-ad0f-ee6ba837a160" xlink:to="loc_us-gaap_DeferredTaxAssetDomain_3f35239a-e3aa-4e23-9e1b-0de48310f304" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherTaxExpenseBenefit_b016e2ef-2645-4661-87ac-c0d525bd626c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OtherTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowanceLineItems_5b135639-3830-4d91-bc87-422e5c93a952" xlink:to="loc_us-gaap_OtherTaxExpenseBenefit_b016e2ef-2645-4661-87ac-c0d525bd626c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/IncomeTaxesOperatingLossCarryforwardsNarrativeDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#IncomeTaxesOperatingLossCarryforwardsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/IncomeTaxesOperatingLossCarryforwardsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwardsLineItems_e8439f7f-c134-4539-a9d7-dab4cf4f21ab" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingLossCarryforwardsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwardsTable_3cec6fbb-93e5-4f1a-8e5c-38ee863f61a8" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingLossCarryforwardsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_e8439f7f-c134-4539-a9d7-dab4cf4f21ab" xlink:to="loc_us-gaap_OperatingLossCarryforwardsTable_3cec6fbb-93e5-4f1a-8e5c-38ee863f61a8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_fe3a311b-1d03-4e48-ae27-7bdd368b632c" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OperatingLossCarryforwardsTable_3cec6fbb-93e5-4f1a-8e5c-38ee863f61a8" xlink:to="loc_srt_RangeAxis_fe3a311b-1d03-4e48-ae27-7bdd368b632c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_fe3a311b-1d03-4e48-ae27-7bdd368b632c_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_fe3a311b-1d03-4e48-ae27-7bdd368b632c" xlink:to="loc_srt_RangeMember_fe3a311b-1d03-4e48-ae27-7bdd368b632c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_088cf4f2-b20e-4489-8f14-d3c63e6fbb16" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_fe3a311b-1d03-4e48-ae27-7bdd368b632c" xlink:to="loc_srt_RangeMember_088cf4f2-b20e-4489-8f14-d3c63e6fbb16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_d84730e4-478f-4b9f-af92-bfb7a84ddbc8" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_088cf4f2-b20e-4489-8f14-d3c63e6fbb16" xlink:to="loc_srt_MinimumMember_d84730e4-478f-4b9f-af92-bfb7a84ddbc8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_794c9cf4-2a4c-4e70-bdb4-9550614beaa3" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_088cf4f2-b20e-4489-8f14-d3c63e6fbb16" xlink:to="loc_srt_MaximumMember_794c9cf4-2a4c-4e70-bdb4-9550614beaa3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_681fda4d-c1b7-4362-854c-53d04c16a01f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OperatingLossCarryforwardsTable_3cec6fbb-93e5-4f1a-8e5c-38ee863f61a8" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_681fda4d-c1b7-4362-854c-53d04c16a01f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_681fda4d-c1b7-4362-854c-53d04c16a01f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_681fda4d-c1b7-4362-854c-53d04c16a01f" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_681fda4d-c1b7-4362-854c-53d04c16a01f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_d7b65f8f-f50c-4cf9-9e43-58e92bf21965" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_681fda4d-c1b7-4362-854c-53d04c16a01f" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_d7b65f8f-f50c-4cf9-9e43-58e92bf21965" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StateAndLocalJurisdictionMember_f23b845c-f467-4d37-bb7a-2f6ef7cca2b9" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_StateAndLocalJurisdictionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_d7b65f8f-f50c-4cf9-9e43-58e92bf21965" xlink:to="loc_us-gaap_StateAndLocalJurisdictionMember_f23b845c-f467-4d37-bb7a-2f6ef7cca2b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCountryMember_a25063f7-0a13-4c66-a3c1-82d17ee6b702" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_d7b65f8f-f50c-4cf9-9e43-58e92bf21965" xlink:to="loc_us-gaap_ForeignCountryMember_a25063f7-0a13-4c66-a3c1-82d17ee6b702" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwards_d21f6e2f-9fe6-4398-94bf-19d6f5937f1c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingLossCarryforwards"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_e8439f7f-c134-4539-a9d7-dab4cf4f21ab" xlink:to="loc_us-gaap_OperatingLossCarryforwards_d21f6e2f-9fe6-4398-94bf-19d6f5937f1c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwardsExpirationDate_7e48270d-fddf-4a79-905d-b07b6c7c362f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OperatingLossCarryforwardsExpirationDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_e8439f7f-c134-4539-a9d7-dab4cf4f21ab" xlink:to="loc_us-gaap_OperatingLossCarryforwardsExpirationDate_7e48270d-fddf-4a79-905d-b07b6c7c362f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsForeign_f4f84dbf-d120-42c5-be4a-2fee212b593e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsForeign"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_e8439f7f-c134-4539-a9d7-dab4cf4f21ab" xlink:to="loc_us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsForeign_f4f84dbf-d120-42c5-be4a-2fee212b593e" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/IncomeTaxesUnrecognizedTaxBenefitsNarrativeDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#IncomeTaxesUnrecognizedTaxBenefitsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/IncomeTaxesUnrecognizedTaxBenefitsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxContingencyLineItems_2abd0bff-4164-44d6-8d23-a02ef269e070" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxContingencyLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxContingencyTable_12a12a52-70b2-4e85-a058-df58b90c38f3" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxContingencyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_2abd0bff-4164-44d6-8d23-a02ef269e070" xlink:to="loc_us-gaap_IncomeTaxContingencyTable_12a12a52-70b2-4e85-a058-df58b90c38f3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityAxis_09ae2093-9a62-44f6-9edb-e11769c3fd6d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxContingencyTable_12a12a52-70b2-4e85-a058-df58b90c38f3" xlink:to="loc_us-gaap_IncomeTaxAuthorityAxis_09ae2093-9a62-44f6-9edb-e11769c3fd6d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_09ae2093-9a62-44f6-9edb-e11769c3fd6d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_09ae2093-9a62-44f6-9edb-e11769c3fd6d" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_09ae2093-9a62-44f6-9edb-e11769c3fd6d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxAuthorityDomain_fcf938b5-3208-4a5a-8029-1c4fab5cb5fc" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_IncomeTaxAuthorityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeTaxAuthorityAxis_09ae2093-9a62-44f6-9edb-e11769c3fd6d" xlink:to="loc_us-gaap_IncomeTaxAuthorityDomain_fcf938b5-3208-4a5a-8029-1c4fab5cb5fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCountryMember_c078f255-dac2-4958-8dd8-04118b747503" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ForeignCountryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxAuthorityDomain_fcf938b5-3208-4a5a-8029-1c4fab5cb5fc" xlink:to="loc_us-gaap_ForeignCountryMember_c078f255-dac2-4958-8dd8-04118b747503" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_071564fa-65e2-47ae-8000-23217aba8f73" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_IncomeTaxContingencyTable_12a12a52-70b2-4e85-a058-df58b90c38f3" xlink:to="loc_srt_RangeAxis_071564fa-65e2-47ae-8000-23217aba8f73" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_071564fa-65e2-47ae-8000-23217aba8f73_default" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_071564fa-65e2-47ae-8000-23217aba8f73" xlink:to="loc_srt_RangeMember_071564fa-65e2-47ae-8000-23217aba8f73_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_1cf6bb40-e18b-4f7e-a8cb-b80a112a60bf" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_071564fa-65e2-47ae-8000-23217aba8f73" xlink:to="loc_srt_RangeMember_1cf6bb40-e18b-4f7e-a8cb-b80a112a60bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_29295ae2-9b0d-42a9-9a3c-8ea923628d62" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_1cf6bb40-e18b-4f7e-a8cb-b80a112a60bf" xlink:to="loc_srt_MinimumMember_29295ae2-9b0d-42a9-9a3c-8ea923628d62" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_db20e7db-82af-4a85-ba1d-965b03ddff98" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_1cf6bb40-e18b-4f7e-a8cb-b80a112a60bf" xlink:to="loc_srt_MaximumMember_db20e7db-82af-4a85-ba1d-965b03ddff98" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefits_8380f9d4-2057-4d89-a807-08e807fdd50d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrecognizedTaxBenefits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_2abd0bff-4164-44d6-8d23-a02ef269e070" xlink:to="loc_us-gaap_UnrecognizedTaxBenefits_8380f9d4-2057-4d89-a807-08e807fdd50d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_e265ec37-4053-47a9-85ab-346d7f01ffa0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_2abd0bff-4164-44d6-8d23-a02ef269e070" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate_e265ec37-4053-47a9-85ab-346d7f01ffa0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_ae94f608-5615-4093-af68-d584256acedb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_2abd0bff-4164-44d6-8d23-a02ef269e070" xlink:to="loc_us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued_ae94f608-5615-4093-af68-d584256acedb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OpenTaxYear_e42bc517-c53f-4525-aba6-d195132e3305" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_OpenTaxYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeTaxContingencyLineItems_2abd0bff-4164-44d6-8d23-a02ef269e070" xlink:to="loc_us-gaap_OpenTaxYear_e42bc517-c53f-4525-aba6-d195132e3305" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/SubsequentEventsSaleofBusinessDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#SubsequentEventsSaleofBusinessDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SubsequentEventsSaleofBusinessDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_ead28c74-4724-434e-a2ac-c8d187da23ea" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_eef30131-8176-42ad-afd3-2128a9be4e06" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_ead28c74-4724-434e-a2ac-c8d187da23ea" xlink:to="loc_us-gaap_SubsequentEventTable_eef30131-8176-42ad-afd3-2128a9be4e06" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_4c85b4af-ac06-4400-ab7e-92a8ffe09450" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_eef30131-8176-42ad-afd3-2128a9be4e06" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_4c85b4af-ac06-4400-ab7e-92a8ffe09450" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_4c85b4af-ac06-4400-ab7e-92a8ffe09450_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_4c85b4af-ac06-4400-ab7e-92a8ffe09450" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_4c85b4af-ac06-4400-ab7e-92a8ffe09450_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_2af1d432-27e7-4868-8b5e-050a726c20ab" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_4c85b4af-ac06-4400-ab7e-92a8ffe09450" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_2af1d432-27e7-4868-8b5e-050a726c20ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_3c5465ca-0d76-43c0-aae4-d646b7efb5b0" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_2af1d432-27e7-4868-8b5e-050a726c20ab" xlink:to="loc_us-gaap_SubsequentEventMember_3c5465ca-0d76-43c0-aae4-d646b7efb5b0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventsDate_0819f28d-40ea-489c-b41a-0cbf07b96a5f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventsDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_ead28c74-4724-434e-a2ac-c8d187da23ea" xlink:to="loc_us-gaap_SubsequentEventsDate_0819f28d-40ea-489c-b41a-0cbf07b96a5f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromSalesOfBusinessAffiliateAndProductiveAssets_b8c231b3-bea7-42de-80a2-9a322bc6df7e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ProceedsFromSalesOfBusinessAffiliateAndProductiveAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_ead28c74-4724-434e-a2ac-c8d187da23ea" xlink:to="loc_us-gaap_ProceedsFromSalesOfBusinessAffiliateAndProductiveAssets_b8c231b3-bea7-42de-80a2-9a322bc6df7e" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/SubsequentEventsAcqusitionDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#SubsequentEventsAcqusitionDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SubsequentEventsAcqusitionDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_6b9d765d-3d82-484f-bc1f-33b53f095226" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_c5e3a2a6-ec7b-4891-a26c-f166b844d9aa" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_6b9d765d-3d82-484f-bc1f-33b53f095226" xlink:to="loc_us-gaap_SubsequentEventTable_c5e3a2a6-ec7b-4891-a26c-f166b844d9aa" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_a919e758-a40f-49ec-836e-6d12ca034a55" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_c5e3a2a6-ec7b-4891-a26c-f166b844d9aa" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_a919e758-a40f-49ec-836e-6d12ca034a55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_a919e758-a40f-49ec-836e-6d12ca034a55_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_a919e758-a40f-49ec-836e-6d12ca034a55" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_a919e758-a40f-49ec-836e-6d12ca034a55_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b0dcbfa3-fcbb-4cc1-824e-6218b19d0a45" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_a919e758-a40f-49ec-836e-6d12ca034a55" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b0dcbfa3-fcbb-4cc1-824e-6218b19d0a45" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_GMTAerospaceMember_c38d604c-4b3c-43ff-b98f-d66c1b225a2e" xlink:href="trs-20241231.xsd#trs_GMTAerospaceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_b0dcbfa3-fcbb-4cc1-824e-6218b19d0a45" xlink:to="loc_trs_GMTAerospaceMember_c38d604c-4b3c-43ff-b98f-d66c1b225a2e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_418be1ec-3c94-48e4-85f9-99dd2061e423" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_c5e3a2a6-ec7b-4891-a26c-f166b844d9aa" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_418be1ec-3c94-48e4-85f9-99dd2061e423" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_418be1ec-3c94-48e4-85f9-99dd2061e423_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_418be1ec-3c94-48e4-85f9-99dd2061e423" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_418be1ec-3c94-48e4-85f9-99dd2061e423_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_39225019-47fa-4bac-a1aa-de6c15628a57" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_418be1ec-3c94-48e4-85f9-99dd2061e423" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_39225019-47fa-4bac-a1aa-de6c15628a57" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_120754c4-d719-4648-8ae4-39a368613a58" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_39225019-47fa-4bac-a1aa-de6c15628a57" xlink:to="loc_us-gaap_SubsequentEventMember_120754c4-d719-4648-8ae4-39a368613a58" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_Purchasepricebasedondefinitivesalesagreement_d4ab30ba-da0c-4cea-a321-3eeda9b26856" xlink:href="trs-20241231.xsd#trs_Purchasepricebasedondefinitivesalesagreement"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_6b9d765d-3d82-484f-bc1f-33b53f095226" xlink:to="loc_trs_Purchasepricebasedondefinitivesalesagreement_d4ab30ba-da0c-4cea-a321-3eeda9b26856" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventsDate_58116450-55c3-4ecb-9dcd-f4278de3a9cf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventsDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_6b9d765d-3d82-484f-bc1f-33b53f095226" xlink:to="loc_us-gaap_SubsequentEventsDate_58116450-55c3-4ecb-9dcd-f4278de3a9cf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionRevenueReportedByAcquiredEntityForLastAnnualPeriod_f1580de1-a54a-42a8-aead-4f46ce64c879" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_BusinessAcquisitionRevenueReportedByAcquiredEntityForLastAnnualPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_6b9d765d-3d82-484f-bc1f-33b53f095226" xlink:to="loc_us-gaap_BusinessAcquisitionRevenueReportedByAcquiredEntityForLastAnnualPeriod_f1580de1-a54a-42a8-aead-4f46ce64c879" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_19756e38-f4c1-491a-8544-ea25d61602f5" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_6b9d765d-3d82-484f-bc1f-33b53f095226" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_19756e38-f4c1-491a-8544-ea25d61602f5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_b9122720-136a-48fe-8aa0-743422d39d6c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_6b9d765d-3d82-484f-bc1f-33b53f095226" xlink:to="loc_us-gaap_Revenues_b9122720-136a-48fe-8aa0-743422d39d6c" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/SubsequentEventsDividendsDeclaredDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#SubsequentEventsDividendsDeclaredDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SubsequentEventsDividendsDeclaredDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_1cb32dc1-1410-4460-bee7-098bbb64af8f" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_8da2ee83-5518-4809-9793-175d1a6d110d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_1cb32dc1-1410-4460-bee7-098bbb64af8f" xlink:to="loc_us-gaap_SubsequentEventTable_8da2ee83-5518-4809-9793-175d1a6d110d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_1627f8f5-274e-41c8-9e68-8257dd14e226" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_8da2ee83-5518-4809-9793-175d1a6d110d" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_1627f8f5-274e-41c8-9e68-8257dd14e226" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_1627f8f5-274e-41c8-9e68-8257dd14e226_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_1627f8f5-274e-41c8-9e68-8257dd14e226" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_1627f8f5-274e-41c8-9e68-8257dd14e226_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_d65e9510-a706-4bbd-8553-9490f8ac2549" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_1627f8f5-274e-41c8-9e68-8257dd14e226" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_d65e9510-a706-4bbd-8553-9490f8ac2549" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_877ff820-6cb8-4286-b215-b1ea23e85dec" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_d65e9510-a706-4bbd-8553-9490f8ac2549" xlink:to="loc_us-gaap_SubsequentEventMember_877ff820-6cb8-4286-b215-b1ea23e85dec" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsAxis_6fc8a29e-3ace-40db-a81a-f3a6fae7f1bf" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_8da2ee83-5518-4809-9793-175d1a6d110d" xlink:to="loc_us-gaap_DividendsAxis_6fc8a29e-3ace-40db-a81a-f3a6fae7f1bf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsDomain_6fc8a29e-3ace-40db-a81a-f3a6fae7f1bf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DividendsAxis_6fc8a29e-3ace-40db-a81a-f3a6fae7f1bf" xlink:to="loc_us-gaap_DividendsDomain_6fc8a29e-3ace-40db-a81a-f3a6fae7f1bf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsDomain_75af6d06-4efd-4dc3-b2ad-a8b848eb2523" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DividendsAxis_6fc8a29e-3ace-40db-a81a-f3a6fae7f1bf" xlink:to="loc_us-gaap_DividendsDomain_75af6d06-4efd-4dc3-b2ad-a8b848eb2523" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendDeclaredMember_73f0270b-0c9a-4766-a12e-928b7ec77607" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendDeclaredMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_75af6d06-4efd-4dc3-b2ad-a8b848eb2523" xlink:to="loc_us-gaap_DividendDeclaredMember_73f0270b-0c9a-4766-a12e-928b7ec77607" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_O2025Q1DividendsMember_ef60fe74-e4fc-4808-93ce-14f49e47013b" xlink:href="trs-20241231.xsd#trs_O2025Q1DividendsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DividendsDomain_75af6d06-4efd-4dc3-b2ad-a8b848eb2523" xlink:to="loc_trs_O2025Q1DividendsMember_ef60fe74-e4fc-4808-93ce-14f49e47013b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableDateDeclaredDayMonthAndYear_8a8f1dff-217d-4c01-bc46-e987d1356192" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableDateDeclaredDayMonthAndYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_1cb32dc1-1410-4460-bee7-098bbb64af8f" xlink:to="loc_us-gaap_DividendsPayableDateDeclaredDayMonthAndYear_8a8f1dff-217d-4c01-bc46-e987d1356192" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableAmountPerShare_21ca515d-800b-41d0-9b2b-4a7bad0d40d1" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableAmountPerShare"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_1cb32dc1-1410-4460-bee7-098bbb64af8f" xlink:to="loc_us-gaap_DividendsPayableAmountPerShare_21ca515d-800b-41d0-9b2b-4a7bad0d40d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendPayableDateToBePaidDayMonthAndYear_bbdea99f-7f5e-4afc-ad9a-25c8234076e2" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendPayableDateToBePaidDayMonthAndYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_1cb32dc1-1410-4460-bee7-098bbb64af8f" xlink:to="loc_us-gaap_DividendPayableDateToBePaidDayMonthAndYear_bbdea99f-7f5e-4afc-ad9a-25c8234076e2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_cfb4eb94-34cc-4448-88bc-6453b3a06bfb" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_DividendsPayableDateOfRecordDayMonthAndYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_1cb32dc1-1410-4460-bee7-098bbb64af8f" xlink:to="loc_us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_cfb4eb94-34cc-4448-88bc-6453b3a06bfb" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.trimascorp.com/role/SECScheduleArticle1209ValuationandQualifyingAccountsDetails" xlink:type="simple" xlink:href="trs-20241231.xsd#SECScheduleArticle1209ValuationandQualifyingAccountsDetails"/>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SECScheduleArticle1209ValuationandQualifyingAccountsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_31d48614-7b68-4f2e-b0ec-3f4a1991233f" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ValuationAndQualifyingAccountsDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_81178437-71b9-4459-adfd-0338b55cd32a" xlink:href="https://xbrl.fasb.org/srt/2024/elts/srt-2024.xsd#srt_ValuationAndQualifyingAccountsDisclosureTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_31d48614-7b68-4f2e-b0ec-3f4a1991233f" xlink:to="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_81178437-71b9-4459-adfd-0338b55cd32a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_8ac82950-3834-4c56-9211-bf6094f72eb6" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_81178437-71b9-4459-adfd-0338b55cd32a" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_8ac82950-3834-4c56-9211-bf6094f72eb6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_8ac82950-3834-4c56-9211-bf6094f72eb6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowancesAndReservesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_8ac82950-3834-4c56-9211-bf6094f72eb6" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_8ac82950-3834-4c56-9211-bf6094f72eb6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_6e45da26-b0f3-465f-83b7-62e34f15399b" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowancesAndReservesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_8ac82950-3834-4c56-9211-bf6094f72eb6" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_6e45da26-b0f3-465f-83b7-62e34f15399b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForCreditLossMember_b04ed424-c8e4-43cb-8094-dbf8fe69826d" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AllowanceForCreditLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_6e45da26-b0f3-465f-83b7-62e34f15399b" xlink:to="loc_us-gaap_AllowanceForCreditLossMember_b04ed424-c8e4-43cb-8094-dbf8fe69826d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_797fae6e-a9d3-4148-816d-1b44dc86923c" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowancesAndReservesBalance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_31d48614-7b68-4f2e-b0ec-3f4a1991233f" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesBalance_797fae6e-a9d3-4148-816d-1b44dc86923c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_b4dffb43-b1dc-4d26-a423-ebbe1a1f2730" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_31d48614-7b68-4f2e-b0ec-3f4a1991233f" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_b4dffb43-b1dc-4d26-a423-ebbe1a1f2730" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_b1f0ed75-1925-4bc4-9129-0bba248d476e" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_31d48614-7b68-4f2e-b0ec-3f4a1991233f" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_b1f0ed75-1925-4bc4-9129-0bba248d476e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDeductions_d1664eca-682b-400f-ba51-73e6a5da2075" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_ValuationAllowancesAndReservesDeductions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_31d48614-7b68-4f2e-b0ec-3f4a1991233f" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDeductions_d1664eca-682b-400f-ba51-73e6a5da2075" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-roles-2024.xsd#eedm"/>
  <link:definitionLink xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_AssetsAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet" xlink:type="arc" order="101"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesCurrentAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_LeaseLiabilitiesCurrentPortion_3d104035-7424-4f05-ad8b-0071dd0c22a1" xlink:href="trs-20241231.xsd#trs_LeaseLiabilitiesCurrentPortion"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract" xlink:to="loc_trs_LeaseLiabilitiesCurrentPortion_3d104035-7424-4f05-ad8b-0071dd0c22a1" xlink:type="arc" order="41"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesNoncurrentAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2024/elts/us-gaap-2024.xsd#us-gaap_LiabilitiesNoncurrentAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_trs_LeaseLiabilitiesNoncurrent_107feb5a-3f9e-4b41-a994-30e72f75bd8d" xlink:href="trs-20241231.xsd#trs_LeaseLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesNoncurrentAbstract" xlink:to="loc_trs_LeaseLiabilitiesNoncurrent_107feb5a-3f9e-4b41-a994-30e72f75bd8d" xlink:type="arc" order="91"/>
  </link:definitionLink>
</link:linkbase>
