

<!--XBRL Document Created with Wdesk from Workiva-->
<!-- -->
<link:linkbase xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <link:roleRef roleURI="http://www.trimascorp.com/role/Acquisitions" xlink:href="trs-20170630.xsd#Acquisitions" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/AcquisitionsOtherAcquisitionsDetails" xlink:href="trs-20170630.xsd#AcquisitionsOtherAcquisitionsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/BasisOfPresentation" xlink:href="trs-20170630.xsd#BasisOfPresentation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/CommitmentsAndContingencies" xlink:href="trs-20170630.xsd#CommitmentsAndContingencies" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/CommitmentsAndContingenciesAsbestosClaimantAndSettlementDetails" xlink:href="trs-20170630.xsd#CommitmentsAndContingenciesAsbestosClaimantAndSettlementDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/CommitmentsAndContingenciesAsbestosDamagesSoughtDetails" xlink:href="trs-20170630.xsd#CommitmentsAndContingenciesAsbestosDamagesSoughtDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/CommitmentsAndContingenciesAsbestosNarrativeDetails" xlink:href="trs-20170630.xsd#CommitmentsAndContingenciesAsbestosNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/CommitmentsAndContingenciesOrdinaryCourseClaimsDetails" xlink:href="trs-20170630.xsd#CommitmentsAndContingenciesOrdinaryCourseClaimsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/CommitmentsAndContingenciesTables" xlink:href="trs-20170630.xsd#CommitmentsAndContingenciesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/ConsolidatedBalanceSheetParentheticals" xlink:href="trs-20170630.xsd#ConsolidatedBalanceSheetParentheticals" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/ConsolidatedBalanceSheetStatement" xlink:href="trs-20170630.xsd#ConsolidatedBalanceSheetStatement" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/ConsolidatedStatementOfCashFlowsStatement" xlink:href="trs-20170630.xsd#ConsolidatedStatementOfCashFlowsStatement" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/ConsolidatedStatementOfComprehensiveIncome" xlink:href="trs-20170630.xsd#ConsolidatedStatementOfComprehensiveIncome" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/ConsolidatedStatementOfIncomeStatement" xlink:href="trs-20170630.xsd#ConsolidatedStatementOfIncomeStatement" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/ConsolidatedStatementOfShareholdersEquityStatement" xlink:href="trs-20170630.xsd#ConsolidatedStatementOfShareholdersEquityStatement" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/DefinedBenefitPlans" xlink:href="trs-20170630.xsd#DefinedBenefitPlans" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/DefinedBenefitPlansDefinedBenefitPlansNarrativeDetails" xlink:href="trs-20170630.xsd#DefinedBenefitPlansDefinedBenefitPlansNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/DefinedBenefitPlansNetPeriodicPensionAndPostretirementBenefitCostsDetails" xlink:href="trs-20170630.xsd#DefinedBenefitPlansNetPeriodicPensionAndPostretirementBenefitCostsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/DefinedBenefitPlansTables" xlink:href="trs-20170630.xsd#DefinedBenefitPlansTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/DerivativeInstruments" xlink:href="trs-20170630.xsd#DerivativeInstruments" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/DerivativeInstrumentsDerivativeNarrativeDetails" xlink:href="trs-20170630.xsd#DerivativeInstrumentsDerivativeNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/DerivativeInstrumentsDesignatedAsHedgingFinancialPerformanceDetails" xlink:href="trs-20170630.xsd#DerivativeInstrumentsDesignatedAsHedgingFinancialPerformanceDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/DerivativeInstrumentsDesignatedAsHedgingFinancialPerformanceNarrativeDetails" xlink:href="trs-20170630.xsd#DerivativeInstrumentsDesignatedAsHedgingFinancialPerformanceNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/DerivativeInstrumentsDesignatedAsHedgingFinancialPositionDetails" xlink:href="trs-20170630.xsd#DerivativeInstrumentsDesignatedAsHedgingFinancialPositionDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/DerivativeInstrumentsFairValueMeasurementsDetails" xlink:href="trs-20170630.xsd#DerivativeInstrumentsFairValueMeasurementsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/DerivativeInstrumentsTables" xlink:href="trs-20170630.xsd#DerivativeInstrumentsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/DocumentAndEntityInformationDocument" xlink:href="trs-20170630.xsd#DocumentAndEntityInformationDocument" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/EarningsPerShare" xlink:href="trs-20170630.xsd#EarningsPerShare" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/EarningsPerShareEarningsPerShareDetails" xlink:href="trs-20170630.xsd#EarningsPerShareEarningsPerShareDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/EarningsPerShareEarningsPerShareTables" xlink:href="trs-20170630.xsd#EarningsPerShareEarningsPerShareTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/EquityAwards" xlink:href="trs-20170630.xsd#EquityAwards" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/EquityAwardsRestrictedSharesActivityTableDetails" xlink:href="trs-20170630.xsd#EquityAwardsRestrictedSharesActivityTableDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/EquityAwardsRestrictedSharesNarrativeDetails" xlink:href="trs-20170630.xsd#EquityAwardsRestrictedSharesNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/EquityAwardsStockOptionActivityTableDetails" xlink:href="trs-20170630.xsd#EquityAwardsStockOptionActivityTableDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/EquityAwardsStockOptionsNarrativeDetails" xlink:href="trs-20170630.xsd#EquityAwardsStockOptionsNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/EquityAwardsTables" xlink:href="trs-20170630.xsd#EquityAwardsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/EquityOfferingDetails" xlink:href="trs-20170630.xsd#EquityOfferingDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/EquityOfferingNotes" xlink:href="trs-20170630.xsd#EquityOfferingNotes" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/EquityOfferingTables" xlink:href="trs-20170630.xsd#EquityOfferingTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/FacilityClosuresNarrativeDetails" xlink:href="trs-20170630.xsd#FacilityClosuresNarrativeDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/FacilityClosuresRestructuringAndRelatedActivitiesDisclosureNotes" xlink:href="trs-20170630.xsd#FacilityClosuresRestructuringAndRelatedActivitiesDisclosureNotes" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/GoodwillAndOtherIntangibleAssets" xlink:href="trs-20170630.xsd#GoodwillAndOtherIntangibleAssets" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/GoodwillAndOtherIntangibleAssetsGoodwillAndOtherIntangibleAssetsTables" xlink:href="trs-20170630.xsd#GoodwillAndOtherIntangibleAssetsGoodwillAndOtherIntangibleAssetsTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/GoodwillAndOtherIntangibleAssetsGoodwillRollforwardDetails" xlink:href="trs-20170630.xsd#GoodwillAndOtherIntangibleAssetsGoodwillRollforwardDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/GoodwillAndOtherIntangibleAssetsScheduleOfFiniteLivedIntangibleAssetsAmortizationExpenseDetails" xlink:href="trs-20170630.xsd#GoodwillAndOtherIntangibleAssetsScheduleOfFiniteLivedIntangibleAssetsAmortizationExpenseDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/GoodwillAndOtherIntangibleAssetsScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassDetails" xlink:href="trs-20170630.xsd#GoodwillAndOtherIntangibleAssetsScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/Inventories" xlink:href="trs-20170630.xsd#Inventories" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/InventoriesDetails" xlink:href="trs-20170630.xsd#InventoriesDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/InventoriesTables" xlink:href="trs-20170630.xsd#InventoriesTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/LongTermDebt" xlink:href="trs-20170630.xsd#LongTermDebt" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/LongTermDebtCreditAgreementDetails" xlink:href="trs-20170630.xsd#LongTermDebtCreditAgreementDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/LongTermDebtDebtTableDetails" xlink:href="trs-20170630.xsd#LongTermDebtDebtTableDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/LongTermDebtLongTermDebtTables" xlink:href="trs-20170630.xsd#LongTermDebtLongTermDebtTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/LongTermDebtReceivablesFacilityDetails" xlink:href="trs-20170630.xsd#LongTermDebtReceivablesFacilityDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/NewAccountingPronouncements" xlink:href="trs-20170630.xsd#NewAccountingPronouncements" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/NewAccountingPronouncementsNewAccountingPronouncementsDetails" xlink:href="trs-20170630.xsd#NewAccountingPronouncementsNewAccountingPronouncementsDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/OtherComprehensiveIncomeLossDetails" xlink:href="trs-20170630.xsd#OtherComprehensiveIncomeLossDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/OtherComprehensiveIncomeLossNotes" xlink:href="trs-20170630.xsd#OtherComprehensiveIncomeLossNotes" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/OtherComprehensiveIncomeLossTables" xlink:href="trs-20170630.xsd#OtherComprehensiveIncomeLossTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/PropertyAndEquipmentNet" xlink:href="trs-20170630.xsd#PropertyAndEquipmentNet" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/PropertyAndEquipmentNetDepreciationExpenseTableDetails" xlink:href="trs-20170630.xsd#PropertyAndEquipmentNetDepreciationExpenseTableDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/PropertyAndEquipmentNetPropertyAndEquipmentTableDetails" xlink:href="trs-20170630.xsd#PropertyAndEquipmentNetPropertyAndEquipmentTableDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/PropertyAndEquipmentNetTables" xlink:href="trs-20170630.xsd#PropertyAndEquipmentNetTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/SegmentInformation" xlink:href="trs-20170630.xsd#SegmentInformation" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/SegmentInformationDetails" xlink:href="trs-20170630.xsd#SegmentInformationDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/SegmentInformationTables" xlink:href="trs-20170630.xsd#SegmentInformationTables" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/SubsequentEventDetails" xlink:href="trs-20170630.xsd#SubsequentEventDetails" xlink:type="simple" />
  <link:roleRef roleURI="http://www.trimascorp.com/role/SubsequentEventNotes" xlink:href="trs-20170630.xsd#SubsequentEventNotes" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member" xlink:type="simple" />
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension" xlink:type="simple" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/Acquisitions" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/AcquisitionsOtherAcquisitionsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_D68D89EC750D5B2694015A7F694A5E27" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_9A810325E1B854A6B2CB063F9EC8E14B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D68D89EC750D5B2694015A7F694A5E27" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_9A810325E1B854A6B2CB063F9EC8E14B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_BF22131E27CB56ABA5438BF89D8FE396" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_9A810325E1B854A6B2CB063F9EC8E14B" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_BF22131E27CB56ABA5438BF89D8FE396" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_42C65319295A48F7D666A46654901521_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_BF22131E27CB56ABA5438BF89D8FE396" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_42C65319295A48F7D666A46654901521_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1D462A382D8055C5AE5FD4865C31DAF9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_BF22131E27CB56ABA5438BF89D8FE396" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_1D462A382D8055C5AE5FD4865C31DAF9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_858CAF72676D5B2B90A969241DAD9E47" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_D68D89EC750D5B2694015A7F694A5E27" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired_858CAF72676D5B2B90A969241DAD9E47" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/BasisOfPresentation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/CommitmentsAndContingencies" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/CommitmentsAndContingenciesAsbestosClaimantAndSettlementDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaap_LossContingenciesLineItems_B139370EAEA2547B9272FE8201F548D7" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable_242FFE58820A568EAECE9CFD6DF62520" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_B139370EAEA2547B9272FE8201F548D7" xlink:to="loc_us-gaap_LossContingenciesTable_242FFE58820A568EAECE9CFD6DF62520" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_D9EF94559CF35ABEA4E6E1F7ACC95094" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_242FFE58820A568EAECE9CFD6DF62520" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_D9EF94559CF35ABEA4E6E1F7ACC95094" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_3FCBFA7DF6AC5F6055C9A46656DCB164_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_D9EF94559CF35ABEA4E6E1F7ACC95094" xlink:to="loc_us-gaap_LossContingencyNatureDomain_3FCBFA7DF6AC5F6055C9A46656DCB164_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_FA8C500D6E705CDD928C7EE24B510CC1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_D9EF94559CF35ABEA4E6E1F7ACC95094" xlink:to="loc_us-gaap_LossContingencyNatureDomain_FA8C500D6E705CDD928C7EE24B510CC1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AsbestosIssueMember" xlink:label="loc_us-gaap_AsbestosIssueMember_DF9FB427842553BE9120289A4A673971" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_FA8C500D6E705CDD928C7EE24B510CC1" xlink:to="loc_us-gaap_AsbestosIssueMember_DF9FB427842553BE9120289A4A673971" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyPendingClaimsNumber" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber_04AF7E31B72C57878C934989BE371EAF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_B139370EAEA2547B9272FE8201F548D7" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_04AF7E31B72C57878C934989BE371EAF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNewClaimsFiledNumber" xlink:label="loc_us-gaap_LossContingencyNewClaimsFiledNumber_62776FA15D2852798D978CE804018B8C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_B139370EAEA2547B9272FE8201F548D7" xlink:to="loc_us-gaap_LossContingencyNewClaimsFiledNumber_62776FA15D2852798D978CE804018B8C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyClaimsDismissedNumber" xlink:label="loc_us-gaap_LossContingencyClaimsDismissedNumber_05AA5F5CCFF5544C9C95D1199744CF1A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_B139370EAEA2547B9272FE8201F548D7" xlink:to="loc_us-gaap_LossContingencyClaimsDismissedNumber_05AA5F5CCFF5544C9C95D1199744CF1A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyClaimsSettledNumber" xlink:label="loc_us-gaap_LossContingencyClaimsSettledNumber_379EDC2CD04F50AA9399C2707E546D4F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_B139370EAEA2547B9272FE8201F548D7" xlink:to="loc_us-gaap_LossContingencyClaimsSettledNumber_379EDC2CD04F50AA9399C2707E546D4F" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_LossContingencySettlementAgreementAverageConsideration" xlink:label="loc_trs_LossContingencySettlementAgreementAverageConsideration_C200E2A187705D7CB8E45AF6577B747C" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_B139370EAEA2547B9272FE8201F548D7" xlink:to="loc_trs_LossContingencySettlementAgreementAverageConsideration_C200E2A187705D7CB8E45AF6577B747C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LegalFees" xlink:label="loc_us-gaap_LegalFees_CB92F26D75D65C31882ECFFDE1F26170" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_B139370EAEA2547B9272FE8201F548D7" xlink:to="loc_us-gaap_LegalFees_CB92F26D75D65C31882ECFFDE1F26170" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/CommitmentsAndContingenciesAsbestosDamagesSoughtDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaap_LossContingenciesLineItems_BA4C2AE02369570DA8F7C2BAA4C772F9" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable_AD04B9A53EC9590C86F2202AA472470D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_BA4C2AE02369570DA8F7C2BAA4C772F9" xlink:to="loc_us-gaap_LossContingenciesTable_AD04B9A53EC9590C86F2202AA472470D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_4E566A83683A5305BE1EFFE94EB81D9F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_AD04B9A53EC9590C86F2202AA472470D" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_4E566A83683A5305BE1EFFE94EB81D9F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_169896E2784B05343F45A46655C5CCA7_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_4E566A83683A5305BE1EFFE94EB81D9F" xlink:to="loc_us-gaap_LossContingencyNatureDomain_169896E2784B05343F45A46655C5CCA7_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_184561F65ACC5300841F96FCAF0D1B40" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_4E566A83683A5305BE1EFFE94EB81D9F" xlink:to="loc_us-gaap_LossContingencyNatureDomain_184561F65ACC5300841F96FCAF0D1B40" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AsbestosIssueMember" xlink:label="loc_us-gaap_AsbestosIssueMember_C70AB820B4705EC1A8329735365D2342" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_184561F65ACC5300841F96FCAF0D1B40" xlink:to="loc_us-gaap_AsbestosIssueMember_C70AB820B4705EC1A8329735365D2342" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationStatusAxis" xlink:label="loc_us-gaap_LitigationStatusAxis_D0776B2A85DA56DAAE87FD3E04920FD2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_AD04B9A53EC9590C86F2202AA472470D" xlink:to="loc_us-gaap_LitigationStatusAxis_D0776B2A85DA56DAAE87FD3E04920FD2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationStatusDomain" xlink:label="loc_us-gaap_LitigationStatusDomain_F0EB1FC0A9094169AE25A46655C58EE6_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LitigationStatusAxis_D0776B2A85DA56DAAE87FD3E04920FD2" xlink:to="loc_us-gaap_LitigationStatusDomain_F0EB1FC0A9094169AE25A46655C58EE6_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationStatusDomain" xlink:label="loc_us-gaap_LitigationStatusDomain_00572E9C15545315AC1324A2707A679C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LitigationStatusAxis_D0776B2A85DA56DAAE87FD3E04920FD2" xlink:to="loc_us-gaap_LitigationStatusDomain_00572E9C15545315AC1324A2707A679C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PendingLitigationMember" xlink:label="loc_us-gaap_PendingLitigationMember_7C8F064241365412B46627B275AE42F0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LitigationStatusDomain_00572E9C15545315AC1324A2707A679C" xlink:to="loc_us-gaap_PendingLitigationMember_7C8F064241365412B46627B275AE42F0" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DamagesSoughtTypeAxis" xlink:label="loc_trs_DamagesSoughtTypeAxis_8381662CCF5657DDBEE170D5862AFE8D" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_AD04B9A53EC9590C86F2202AA472470D" xlink:to="loc_trs_DamagesSoughtTypeAxis_8381662CCF5657DDBEE170D5862AFE8D" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DamagesSoughtTypeDomain" xlink:label="loc_trs_DamagesSoughtTypeDomain_9C73AA16F4E01088485DA46655C5ADEF_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_DamagesSoughtTypeAxis_8381662CCF5657DDBEE170D5862AFE8D" xlink:to="loc_trs_DamagesSoughtTypeDomain_9C73AA16F4E01088485DA46655C5ADEF_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DamagesSoughtTypeDomain" xlink:label="loc_trs_DamagesSoughtTypeDomain_19A0C0D73E06598187CF69A89A481333" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_DamagesSoughtTypeAxis_8381662CCF5657DDBEE170D5862AFE8D" xlink:to="loc_trs_DamagesSoughtTypeDomain_19A0C0D73E06598187CF69A89A481333" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_CompensatoryAndPunitiveDamagesMember" xlink:label="loc_trs_CompensatoryAndPunitiveDamagesMember_1857298D57D5516486B9A763326F5094" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtTypeDomain_19A0C0D73E06598187CF69A89A481333" xlink:to="loc_trs_CompensatoryAndPunitiveDamagesMember_1857298D57D5516486B9A763326F5094" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_CompensatoryOnlyDamagesMember" xlink:label="loc_trs_CompensatoryOnlyDamagesMember_192F847A90E851AFBA7858A1533D9C0C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtTypeDomain_19A0C0D73E06598187CF69A89A481333" xlink:to="loc_trs_CompensatoryOnlyDamagesMember_192F847A90E851AFBA7858A1533D9C0C" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_PunitiveOnlyDamagesMember" xlink:label="loc_trs_PunitiveOnlyDamagesMember_FCD0D423171053A08AAAAD086264CED6" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtTypeDomain_19A0C0D73E06598187CF69A89A481333" xlink:to="loc_trs_PunitiveOnlyDamagesMember_FCD0D423171053A08AAAAD086264CED6" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DamagesSoughtRangeAxis" xlink:label="loc_trs_DamagesSoughtRangeAxis_B39771C1FBAB551997EE8640DD0EC49A" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_AD04B9A53EC9590C86F2202AA472470D" xlink:to="loc_trs_DamagesSoughtRangeAxis_B39771C1FBAB551997EE8640DD0EC49A" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DamagesSoughtDomain" xlink:label="loc_trs_DamagesSoughtDomain_33553552601742B7AC41A46655C7C3A4_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_DamagesSoughtRangeAxis_B39771C1FBAB551997EE8640DD0EC49A" xlink:to="loc_trs_DamagesSoughtDomain_33553552601742B7AC41A46655C7C3A4_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DamagesSoughtDomain" xlink:label="loc_trs_DamagesSoughtDomain_9C3B25DDB6355BB581C000F97763B087" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_DamagesSoughtRangeAxis_B39771C1FBAB551997EE8640DD0EC49A" xlink:to="loc_trs_DamagesSoughtDomain_9C3B25DDB6355BB581C000F97763B087" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_Range1Member" xlink:label="loc_trs_Range1Member_5D84A65D255A5109A4CA897C36C55BB4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtDomain_9C3B25DDB6355BB581C000F97763B087" xlink:to="loc_trs_Range1Member_5D84A65D255A5109A4CA897C36C55BB4" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_Range2Member" xlink:label="loc_trs_Range2Member_B96107353A695FD1AB0E6298CEACB232" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtDomain_9C3B25DDB6355BB581C000F97763B087" xlink:to="loc_trs_Range2Member_B96107353A695FD1AB0E6298CEACB232" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_Range3Member" xlink:label="loc_trs_Range3Member_F539F256BB5C5296A062AD09E5044AA1" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtDomain_9C3B25DDB6355BB581C000F97763B087" xlink:to="loc_trs_Range3Member_F539F256BB5C5296A062AD09E5044AA1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_F09AFBF65783577EA3812323C742263C" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_AD04B9A53EC9590C86F2202AA472470D" xlink:to="loc_us-gaap_RangeAxis_F09AFBF65783577EA3812323C742263C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_246E410A8F35E649E042A46655C79F5D_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_F09AFBF65783577EA3812323C742263C" xlink:to="loc_us-gaap_RangeMember_246E410A8F35E649E042A46655C79F5D_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_D742395974BE549D97E93A664FB1E255" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_F09AFBF65783577EA3812323C742263C" xlink:to="loc_us-gaap_RangeMember_D742395974BE549D97E93A664FB1E255" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_F46C037A49AA5138AB0ACEB3A46C2F37" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_D742395974BE549D97E93A664FB1E255" xlink:to="loc_us-gaap_MinimumMember_F46C037A49AA5138AB0ACEB3A46C2F37" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_1156A666D2A05DD6B7745B77EDFA309E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_D742395974BE549D97E93A664FB1E255" xlink:to="loc_us-gaap_MaximumMember_1156A666D2A05DD6B7745B77EDFA309E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyDamagesSoughtValue" xlink:label="loc_us-gaap_LossContingencyDamagesSoughtValue_F7CCD6CF66795AF086F51546A4D68CEE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_BA4C2AE02369570DA8F7C2BAA4C772F9" xlink:to="loc_us-gaap_LossContingencyDamagesSoughtValue_F7CCD6CF66795AF086F51546A4D68CEE" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_LossContingencyNumberofPlaintiffsSpecifyingDamagesSought" xlink:label="loc_trs_LossContingencyNumberofPlaintiffsSpecifyingDamagesSought_514425F994DE5041922D98D51481A0D8" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_BA4C2AE02369570DA8F7C2BAA4C772F9" xlink:to="loc_trs_LossContingencyNumberofPlaintiffsSpecifyingDamagesSought_514425F994DE5041922D98D51481A0D8" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/CommitmentsAndContingenciesAsbestosNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaap_LossContingenciesLineItems_979484C92B9E5C92B0AD74E7760E6DB4" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable_C633A76561085D74AA0597737FE07D68" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_979484C92B9E5C92B0AD74E7760E6DB4" xlink:to="loc_us-gaap_LossContingenciesTable_C633A76561085D74AA0597737FE07D68" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DamagesSoughtTypeAxis" xlink:label="loc_trs_DamagesSoughtTypeAxis_6F84ACCD5E0450D9B1F3821ABD4855B2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_C633A76561085D74AA0597737FE07D68" xlink:to="loc_trs_DamagesSoughtTypeAxis_6F84ACCD5E0450D9B1F3821ABD4855B2" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DamagesSoughtTypeDomain" xlink:label="loc_trs_DamagesSoughtTypeDomain_3ADCC60DF37766940667A4665489257A_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_DamagesSoughtTypeAxis_6F84ACCD5E0450D9B1F3821ABD4855B2" xlink:to="loc_trs_DamagesSoughtTypeDomain_3ADCC60DF37766940667A4665489257A_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DamagesSoughtTypeDomain" xlink:label="loc_trs_DamagesSoughtTypeDomain_A352C75422FB5D8B8383D2412D36B8E9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_DamagesSoughtTypeAxis_6F84ACCD5E0450D9B1F3821ABD4855B2" xlink:to="loc_trs_DamagesSoughtTypeDomain_A352C75422FB5D8B8383D2412D36B8E9" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_PunitiveOnlyDamagesMember" xlink:label="loc_trs_PunitiveOnlyDamagesMember_E8ED3EA88E00523BB08950821400A7DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtTypeDomain_A352C75422FB5D8B8383D2412D36B8E9" xlink:to="loc_trs_PunitiveOnlyDamagesMember_E8ED3EA88E00523BB08950821400A7DE" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_CompensatoryOnlyDamagesMember" xlink:label="loc_trs_CompensatoryOnlyDamagesMember_CD93C133E2DF53B4934F6D4B3C9C643E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DamagesSoughtTypeDomain_A352C75422FB5D8B8383D2412D36B8E9" xlink:to="loc_trs_CompensatoryOnlyDamagesMember_CD93C133E2DF53B4934F6D4B3C9C643E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_005C136C86125B4EB26C2B4A18693A08" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_C633A76561085D74AA0597737FE07D68" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_005C136C86125B4EB26C2B4A18693A08" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_EEBD9B396DC550118359A46654893171_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_005C136C86125B4EB26C2B4A18693A08" xlink:to="loc_us-gaap_LossContingencyNatureDomain_EEBD9B396DC550118359A46654893171_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_39F86A83069D5CD590AC83F7DFE26F9D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_005C136C86125B4EB26C2B4A18693A08" xlink:to="loc_us-gaap_LossContingencyNatureDomain_39F86A83069D5CD590AC83F7DFE26F9D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AsbestosIssueMember" xlink:label="loc_us-gaap_AsbestosIssueMember_F78F4CD3ED2E53E08EF5BD7B0D77A69C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_39F86A83069D5CD590AC83F7DFE26F9D" xlink:to="loc_us-gaap_AsbestosIssueMember_F78F4CD3ED2E53E08EF5BD7B0D77A69C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationStatusAxis" xlink:label="loc_us-gaap_LitigationStatusAxis_518DE055A7BA50D4817395D8925DA04F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_C633A76561085D74AA0597737FE07D68" xlink:to="loc_us-gaap_LitigationStatusAxis_518DE055A7BA50D4817395D8925DA04F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationStatusDomain" xlink:label="loc_us-gaap_LitigationStatusDomain_3F98B5B29B40D093131FA46654899857_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LitigationStatusAxis_518DE055A7BA50D4817395D8925DA04F" xlink:to="loc_us-gaap_LitigationStatusDomain_3F98B5B29B40D093131FA46654899857_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationStatusDomain" xlink:label="loc_us-gaap_LitigationStatusDomain_FE02B0007D1B50F0BF1C8472C33AEFD1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LitigationStatusAxis_518DE055A7BA50D4817395D8925DA04F" xlink:to="loc_us-gaap_LitigationStatusDomain_FE02B0007D1B50F0BF1C8472C33AEFD1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PendingLitigationMember" xlink:label="loc_us-gaap_PendingLitigationMember_221ACF5F50A7543E9995CF3D34619051" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LitigationStatusDomain_FE02B0007D1B50F0BF1C8472C33AEFD1" xlink:to="loc_us-gaap_PendingLitigationMember_221ACF5F50A7543E9995CF3D34619051" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_B548854791B45582ACCFB795F1F74239" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_C633A76561085D74AA0597737FE07D68" xlink:to="loc_us-gaap_RangeAxis_B548854791B45582ACCFB795F1F74239" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_8D20692C285FA9C74ADEA4665489EC5C_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_B548854791B45582ACCFB795F1F74239" xlink:to="loc_us-gaap_RangeMember_8D20692C285FA9C74ADEA4665489EC5C_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_CE6BC899E84150799FAAF225F0DF66D6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_B548854791B45582ACCFB795F1F74239" xlink:to="loc_us-gaap_RangeMember_CE6BC899E84150799FAAF225F0DF66D6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_C569345EBCDC505D9174604CB52A339E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_CE6BC899E84150799FAAF225F0DF66D6" xlink:to="loc_us-gaap_MinimumMember_C569345EBCDC505D9174604CB52A339E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_2A1674D4974250A18021349570411A1F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_CE6BC899E84150799FAAF225F0DF66D6" xlink:to="loc_us-gaap_MaximumMember_2A1674D4974250A18021349570411A1F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyPendingClaimsNumber" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber_189BC56DFBD750A48A9DD7985276481D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_979484C92B9E5C92B0AD74E7760E6DB4" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_189BC56DFBD750A48A9DD7985276481D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNumberOfPlaintiffs" xlink:label="loc_us-gaap_LossContingencyNumberOfPlaintiffs_5C9674E315E2544DAEB5615828C361AE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_979484C92B9E5C92B0AD74E7760E6DB4" xlink:to="loc_us-gaap_LossContingencyNumberOfPlaintiffs_5C9674E315E2544DAEB5615828C361AE" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_LossContingencyNumberofPlaintiffsSpecifyingDamagesSought" xlink:label="loc_trs_LossContingencyNumberofPlaintiffsSpecifyingDamagesSought_D47C5D1E2023595EB16D9B0588892448" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_979484C92B9E5C92B0AD74E7760E6DB4" xlink:to="loc_trs_LossContingencyNumberofPlaintiffsSpecifyingDamagesSought_D47C5D1E2023595EB16D9B0588892448" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationSettlementExpense" xlink:label="loc_us-gaap_LitigationSettlementExpense_10B5596C1B7A58A8BF41F2505FFFA650" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_979484C92B9E5C92B0AD74E7760E6DB4" xlink:to="loc_us-gaap_LitigationSettlementExpense_10B5596C1B7A58A8BF41F2505FFFA650" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_PercentageOfSettlementAndDefenseCostsCoveredByInsurance" xlink:label="loc_trs_PercentageOfSettlementAndDefenseCostsCoveredByInsurance_19365F63FF52592492B2E0863ED8E638" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_979484C92B9E5C92B0AD74E7760E6DB4" xlink:to="loc_trs_PercentageOfSettlementAndDefenseCostsCoveredByInsurance_19365F63FF52592492B2E0863ED8E638" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_EstimatedTimeuntilPrimaryInsuranceisExhausted" xlink:label="loc_trs_EstimatedTimeuntilPrimaryInsuranceisExhausted_24D1F7E9C5465E8F9E8FEDD1B73B943B" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_979484C92B9E5C92B0AD74E7760E6DB4" xlink:to="loc_trs_EstimatedTimeuntilPrimaryInsuranceisExhausted_24D1F7E9C5465E8F9E8FEDD1B73B943B" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/CommitmentsAndContingenciesOrdinaryCourseClaimsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesLineItems" xlink:label="loc_us-gaap_LossContingenciesLineItems_229E1AD8378D5C6A80E171F24037D8A7" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesTable" xlink:label="loc_us-gaap_LossContingenciesTable_64835B18CC6A596ABFB9CAA0877622A0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_229E1AD8378D5C6A80E171F24037D8A7" xlink:to="loc_us-gaap_LossContingenciesTable_64835B18CC6A596ABFB9CAA0877622A0" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationCaseAxis" xlink:label="loc_us-gaap_LitigationCaseAxis_35539671CADD53C89FE9EEAAD9C797EF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_64835B18CC6A596ABFB9CAA0877622A0" xlink:to="loc_us-gaap_LitigationCaseAxis_35539671CADD53C89FE9EEAAD9C797EF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationCaseTypeDomain" xlink:label="loc_us-gaap_LitigationCaseTypeDomain_75AA5B664F9DEC9A69CFA4665500316B_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LitigationCaseAxis_35539671CADD53C89FE9EEAAD9C797EF" xlink:to="loc_us-gaap_LitigationCaseTypeDomain_75AA5B664F9DEC9A69CFA4665500316B_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationCaseTypeDomain" xlink:label="loc_us-gaap_LitigationCaseTypeDomain_439A27ECC2745207BFF6F39C3314DA47" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LitigationCaseAxis_35539671CADD53C89FE9EEAAD9C797EF" xlink:to="loc_us-gaap_LitigationCaseTypeDomain_439A27ECC2745207BFF6F39C3314DA47" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationStatusAxis" xlink:label="loc_us-gaap_LitigationStatusAxis_8AB11F12020657F791D6431AC481F5BB" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_64835B18CC6A596ABFB9CAA0877622A0" xlink:to="loc_us-gaap_LitigationStatusAxis_8AB11F12020657F791D6431AC481F5BB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationStatusDomain" xlink:label="loc_us-gaap_LitigationStatusDomain_01AE6704E8E33372C5D7A4665500736E_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LitigationStatusAxis_8AB11F12020657F791D6431AC481F5BB" xlink:to="loc_us-gaap_LitigationStatusDomain_01AE6704E8E33372C5D7A4665500736E_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LitigationStatusDomain" xlink:label="loc_us-gaap_LitigationStatusDomain_BBF7E77FD31758ABB2C20A7A395F4323" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LitigationStatusAxis_8AB11F12020657F791D6431AC481F5BB" xlink:to="loc_us-gaap_LitigationStatusDomain_BBF7E77FD31758ABB2C20A7A395F4323" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_180D95FF9DA659959BD927741112E680" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_64835B18CC6A596ABFB9CAA0877622A0" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_180D95FF9DA659959BD927741112E680" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_2F2A5F6FD31CE2A27015A4665500D116_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_180D95FF9DA659959BD927741112E680" xlink:to="loc_us-gaap_LossContingencyNatureDomain_2F2A5F6FD31CE2A27015A4665500D116_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyNatureDomain" xlink:label="loc_us-gaap_LossContingencyNatureDomain_EDBE9AF9433E59799AC2017CF89C29EA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_180D95FF9DA659959BD927741112E680" xlink:to="loc_us-gaap_LossContingencyNatureDomain_EDBE9AF9433E59799AC2017CF89C29EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LossContingencyDamagesAwardedValue" xlink:label="loc_us-gaap_LossContingencyDamagesAwardedValue_F330DE10D0A6554AAB972A7872B71D23" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_229E1AD8378D5C6A80E171F24037D8A7" xlink:to="loc_us-gaap_LossContingencyDamagesAwardedValue_F330DE10D0A6554AAB972A7872B71D23" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/CommitmentsAndContingenciesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/ConsolidatedBalanceSheetParentheticals" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_9BAF3B1AC8B450D6A6700A64F40D66A5" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_397325E986275DBF9A0676C0406DAF5D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_9BAF3B1AC8B450D6A6700A64F40D66A5" xlink:to="loc_us-gaap_StatementTable_397325E986275DBF9A0676C0406DAF5D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_6E824C7943A159F29E9A27E9AA5D58A5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_397325E986275DBF9A0676C0406DAF5D" xlink:to="loc_us-gaap_StatementScenarioAxis_6E824C7943A159F29E9A27E9AA5D58A5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_F9DB07D21CAD19C37103A46656C9EC7B_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_6E824C7943A159F29E9A27E9AA5D58A5" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_F9DB07D21CAD19C37103A46656C9EC7B_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_85F004D6E1925BE0802772841F5B51E8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_6E824C7943A159F29E9A27E9AA5D58A5" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_85F004D6E1925BE0802772841F5B51E8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="loc_us-gaap_AssetsCurrentAbstract_246CB5CA97D350B789CD88B03A8C0DC4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_9BAF3B1AC8B450D6A6700A64F40D66A5" xlink:to="loc_us-gaap_AssetsCurrentAbstract_246CB5CA97D350B789CD88B03A8C0DC4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_382F4FBE586C590F80CEA0C9FB8C4E26" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_246CB5CA97D350B789CD88B03A8C0DC4" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_382F4FBE586C590F80CEA0C9FB8C4E26" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_5331F3C0E6155A95B83484C2AB30BB8D" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_9BAF3B1AC8B450D6A6700A64F40D66A5" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_5331F3C0E6155A95B83484C2AB30BB8D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_PreferredStockParOrStatedValuePerShare_3725D2E3AD975924BD77F219B27585ED" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_5331F3C0E6155A95B83484C2AB30BB8D" xlink:to="loc_us-gaap_PreferredStockParOrStatedValuePerShare_3725D2E3AD975924BD77F219B27585ED" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_A0B907783181546D9173F0411C446F83" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_5331F3C0E6155A95B83484C2AB30BB8D" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_A0B907783181546D9173F0411C446F83" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:label="loc_us-gaap_PreferredStockSharesIssued_33600159EBD05FA581F17247AF1CA4ED" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_5331F3C0E6155A95B83484C2AB30BB8D" xlink:to="loc_us-gaap_PreferredStockSharesIssued_33600159EBD05FA581F17247AF1CA4ED" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_69D77EB6A52456778CCF5E2A34E4A83D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_5331F3C0E6155A95B83484C2AB30BB8D" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_69D77EB6A52456778CCF5E2A34E4A83D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:label="loc_us-gaap_CommonStockParOrStatedValuePerShare_976900DFA44E5838AC63A020CF49CC81" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_5331F3C0E6155A95B83484C2AB30BB8D" xlink:to="loc_us-gaap_CommonStockParOrStatedValuePerShare_976900DFA44E5838AC63A020CF49CC81" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_2395B918DA6259909F1534CBEA630DC7" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_5331F3C0E6155A95B83484C2AB30BB8D" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_2395B918DA6259909F1534CBEA630DC7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:label="loc_us-gaap_CommonStockSharesIssued_F39871A5892C556B8F53545A74A64802" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_5331F3C0E6155A95B83484C2AB30BB8D" xlink:to="loc_us-gaap_CommonStockSharesIssued_F39871A5892C556B8F53545A74A64802" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_B59BC91F7F5A5814B3B2031CFBD6FD87" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_5331F3C0E6155A95B83484C2AB30BB8D" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_B59BC91F7F5A5814B3B2031CFBD6FD87" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/ConsolidatedBalanceSheetStatement" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_0301CE4506EB032CD95D7A8CC0A6144F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_471B73F99A072BF3577B7A8CC0A2ABDB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_0301CE4506EB032CD95D7A8CC0A6144F" xlink:to="loc_us-gaap_StatementTable_471B73F99A072BF3577B7A8CC0A2ABDB" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_08FBDE5E585217B9DC3A7A8CC0A2CD9D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_471B73F99A072BF3577B7A8CC0A2ABDB" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_08FBDE5E585217B9DC3A7A8CC0A2CD9D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_8ADB839CB2DD14E9ED837A8CC0A31792_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_08FBDE5E585217B9DC3A7A8CC0A2CD9D" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_8ADB839CB2DD14E9ED837A8CC0A31792_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_8ADB839CB2DD14E9ED837A8CC0A31792" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_08FBDE5E585217B9DC3A7A8CC0A2CD9D" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_8ADB839CB2DD14E9ED837A8CC0A31792" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsAbstract" xlink:label="loc_us-gaap_AssetsAbstract_9572FF9486E2BC45105F7A8CC0A7C7EE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0301CE4506EB032CD95D7A8CC0A6144F" xlink:to="loc_us-gaap_AssetsAbstract_9572FF9486E2BC45105F7A8CC0A7C7EE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:label="loc_us-gaap_AssetsCurrentAbstract_296468F96EA731EC4F247A8CC0A72267" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_9572FF9486E2BC45105F7A8CC0A7C7EE" xlink:to="loc_us-gaap_AssetsCurrentAbstract_296468F96EA731EC4F247A8CC0A72267" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_47DAEF2186D83D7E85297A8CC0A78120" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_296468F96EA731EC4F247A8CC0A72267" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_47DAEF2186D83D7E85297A8CC0A78120" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_0F8CCB772EC8469C6AF47A8CC0A77F8E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_296468F96EA731EC4F247A8CC0A72267" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_0F8CCB772EC8469C6AF47A8CC0A77F8E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InventoryNet" xlink:label="loc_us-gaap_InventoryNet_C3AEB703F073496597E07A8CC0A7C698" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_296468F96EA731EC4F247A8CC0A72267" xlink:to="loc_us-gaap_InventoryNet_C3AEB703F073496597E07A8CC0A7C698" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:label="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_DEC98032E346D7EBD7157A8CC0A715DF" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_296468F96EA731EC4F247A8CC0A72267" xlink:to="loc_us-gaap_PrepaidExpenseAndOtherAssetsCurrent_DEC98032E346D7EBD7157A8CC0A715DF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AssetsCurrent" xlink:label="loc_us-gaap_AssetsCurrent_833FB7D181DFA6899ED77A8CC0A7175C" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsCurrentAbstract_296468F96EA731EC4F247A8CC0A72267" xlink:to="loc_us-gaap_AssetsCurrent_833FB7D181DFA6899ED77A8CC0A7175C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_3406958F6BDF53EE59DB7A8CC0A87B0F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_9572FF9486E2BC45105F7A8CC0A7C7EE" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_3406958F6BDF53EE59DB7A8CC0A87B0F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_D3700F4EBCA6192C7CE37A8CC0A81021" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_9572FF9486E2BC45105F7A8CC0A7C7EE" xlink:to="loc_us-gaap_Goodwill_D3700F4EBCA6192C7CE37A8CC0A81021" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_B70E96BE39B1F0C6CA7D7A8CC0A8E7AC" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_9572FF9486E2BC45105F7A8CC0A7C7EE" xlink:to="loc_us-gaap_IntangibleAssetsNetExcludingGoodwill_B70E96BE39B1F0C6CA7D7A8CC0A8E7AC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherAssetsNoncurrent" xlink:label="loc_us-gaap_OtherAssetsNoncurrent_2683FF591EAC380973947A8CC0A8CA5B" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_9572FF9486E2BC45105F7A8CC0A7C7EE" xlink:to="loc_us-gaap_OtherAssetsNoncurrent_2683FF591EAC380973947A8CC0A8CA5B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Assets" xlink:label="loc_us-gaap_Assets_914C11A7EECA1D029FFD7A8CC0A8B6C3" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetsAbstract_9572FF9486E2BC45105F7A8CC0A7C7EE" xlink:to="loc_us-gaap_Assets_914C11A7EECA1D029FFD7A8CC0A8B6C3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquityAbstract" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ADFFD08B8892759298B37A8CC0A81CFB" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_0301CE4506EB032CD95D7A8CC0A6144F" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ADFFD08B8892759298B37A8CC0A81CFB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:label="loc_us-gaap_LiabilitiesCurrentAbstract_7B368A757C93AE77255D7A8CC0A87DC6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ADFFD08B8892759298B37A8CC0A81CFB" xlink:to="loc_us-gaap_LiabilitiesCurrentAbstract_7B368A757C93AE77255D7A8CC0A87DC6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtCurrent" xlink:label="loc_us-gaap_DebtCurrent_3AB094F7DA2ADD50E0817A8CC0A88E25" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_7B368A757C93AE77255D7A8CC0A87DC6" xlink:to="loc_us-gaap_DebtCurrent_3AB094F7DA2ADD50E0817A8CC0A88E25" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:label="loc_us-gaap_AccountsPayableCurrent_020AC617AFD2DD8364727A8CC0AA9D88" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_7B368A757C93AE77255D7A8CC0A87DC6" xlink:to="loc_us-gaap_AccountsPayableCurrent_020AC617AFD2DD8364727A8CC0AA9D88" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:label="loc_us-gaap_AccruedLiabilitiesCurrent_06294CD3C0717E1225577A8CC0AA0FA1" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_7B368A757C93AE77255D7A8CC0A87DC6" xlink:to="loc_us-gaap_AccruedLiabilitiesCurrent_06294CD3C0717E1225577A8CC0AA0FA1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:label="loc_us-gaap_LiabilitiesCurrent_AAA339570946E7A191D67A8CC0AAD86C" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesCurrentAbstract_7B368A757C93AE77255D7A8CC0A87DC6" xlink:to="loc_us-gaap_LiabilitiesCurrent_AAA339570946E7A191D67A8CC0AAD86C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_4221B974B8C29B6900D67A8CC0AB1F3A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ADFFD08B8892759298B37A8CC0A81CFB" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_4221B974B8C29B6900D67A8CC0AB1F3A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredTaxLiabilitiesNoncurrent" xlink:label="loc_us-gaap_DeferredTaxLiabilitiesNoncurrent_BE0E472E6F887C45C7A47A8CC0AB00F4" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ADFFD08B8892759298B37A8CC0A81CFB" xlink:to="loc_us-gaap_DeferredTaxLiabilitiesNoncurrent_BE0E472E6F887C45C7A47A8CC0AB00F4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:label="loc_us-gaap_OtherLiabilitiesNoncurrent_EA1CC4B6C0A001D781F77A8CC0ABE6DF" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ADFFD08B8892759298B37A8CC0A81CFB" xlink:to="loc_us-gaap_OtherLiabilitiesNoncurrent_EA1CC4B6C0A001D781F77A8CC0ABE6DF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Liabilities" xlink:label="loc_us-gaap_Liabilities_A91AB1A05647109E53F17A8CC0ABFBB8" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ADFFD08B8892759298B37A8CC0A81CFB" xlink:to="loc_us-gaap_Liabilities_A91AB1A05647109E53F17A8CC0ABFBB8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PreferredStockValue" xlink:label="loc_us-gaap_PreferredStockValue_5A8FBF81B5DC04F59D927A8CC0ABAC3A" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ADFFD08B8892759298B37A8CC0A81CFB" xlink:to="loc_us-gaap_PreferredStockValue_5A8FBF81B5DC04F59D927A8CC0ABAC3A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockValue" xlink:label="loc_us-gaap_CommonStockValue_3380E5C5F69E62761C377A8CC0ABB83A" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ADFFD08B8892759298B37A8CC0A81CFB" xlink:to="loc_us-gaap_CommonStockValue_3380E5C5F69E62761C377A8CC0ABB83A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:label="loc_us-gaap_AdditionalPaidInCapitalCommonStock_0454D856D899E9D21F657A8CC0ABFF10" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ADFFD08B8892759298B37A8CC0A81CFB" xlink:to="loc_us-gaap_AdditionalPaidInCapitalCommonStock_0454D856D899E9D21F657A8CC0ABFF10" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:label="loc_us-gaap_RetainedEarningsAccumulatedDeficit_255DA2782A2E5459E9C67A8CC0AB434D" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ADFFD08B8892759298B37A8CC0A81CFB" xlink:to="loc_us-gaap_RetainedEarningsAccumulatedDeficit_255DA2782A2E5459E9C67A8CC0AB434D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_713806CFDD792FA230247A8CC0AB6C5F" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ADFFD08B8892759298B37A8CC0A81CFB" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_713806CFDD792FA230247A8CC0AB6C5F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockholdersEquity" xlink:label="loc_us-gaap_StockholdersEquity_A07D45A23AD6BE399F7C7A8CC0AB4C23" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ADFFD08B8892759298B37A8CC0A81CFB" xlink:to="loc_us-gaap_StockholdersEquity_A07D45A23AD6BE399F7C7A8CC0AB4C23" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:label="loc_us-gaap_LiabilitiesAndStockholdersEquity_9023A322D445166E116F7A8CC0AB4553" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAndStockholdersEquityAbstract_ADFFD08B8892759298B37A8CC0A81CFB" xlink:to="loc_us-gaap_LiabilitiesAndStockholdersEquity_9023A322D445166E116F7A8CC0AB4553" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/ConsolidatedStatementOfCashFlowsStatement" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_DD3ADCF87A1CBFDA448A7A9688AFFC38" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_F0489E83ACF8A0C8383F7A9688AF2FFD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_DD3ADCF87A1CBFDA448A7A9688AFFC38" xlink:to="loc_us-gaap_StatementTable_F0489E83ACF8A0C8383F7A9688AF2FFD" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_2C04C2E955B4D4D15D017A9688AF1947" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_F0489E83ACF8A0C8383F7A9688AF2FFD" xlink:to="loc_us-gaap_StatementScenarioAxis_2C04C2E955B4D4D15D017A9688AF1947" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_3CEFA4012C2FEB91CB0F7A9688AFC309_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_2C04C2E955B4D4D15D017A9688AF1947" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_3CEFA4012C2FEB91CB0F7A9688AFC309_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_3CEFA4012C2FEB91CB0F7A9688AFC309" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_2C04C2E955B4D4D15D017A9688AF1947" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_3CEFA4012C2FEB91CB0F7A9688AFC309" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_6D5D22D3BACE180957F87A9688AF207D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_DD3ADCF87A1CBFDA448A7A9688AFFC38" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_6D5D22D3BACE180957F87A9688AF207D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_5866CFB5507625601EAC7A9688AF86AA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_6D5D22D3BACE180957F87A9688AF207D" xlink:to="loc_us-gaap_ProfitLoss_5866CFB5507625601EAC7A9688AF86AA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract" xlink:label="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_6D5D22D3BACE180957F87A9688AF207D" xlink:to="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GainLossOnDispositionOfAssets1" xlink:label="loc_us-gaap_GainLossOnDispositionOfAssets1_BAC04974DC7C18E377037A9688B4127D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:to="loc_us-gaap_GainLossOnDispositionOfAssets1_BAC04974DC7C18E377037A9688B4127D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Depreciation" xlink:label="loc_us-gaap_Depreciation_C4578414776663EF8CF47A9688B4C15B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:to="loc_us-gaap_Depreciation_C4578414776663EF8CF47A9688B4C15B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_7158F61B11AA3FFA97FF7A9688B48E81" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_7158F61B11AA3FFA97FF7A9688B48E81" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AmortizationOfFinancingCostsAndDiscounts" xlink:label="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts_2E06DED9E8E5753A9DF27A9688B45850" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:to="loc_us-gaap_AmortizationOfFinancingCostsAndDiscounts_2E06DED9E8E5753A9DF27A9688B45850" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredIncomeTaxesAndTaxCredits" xlink:label="loc_us-gaap_DeferredIncomeTaxesAndTaxCredits_3A965AB0C65C4CF244367A9688B4A1BF" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:to="loc_us-gaap_DeferredIncomeTaxesAndTaxCredits_3A965AB0C65C4CF244367A9688B4A1BF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:label="loc_us-gaap_ShareBasedCompensation_22278A2E696D7971BE747A9688B461E3" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:to="loc_us-gaap_ShareBasedCompensation_22278A2E696D7971BE747A9688B461E3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities" xlink:label="loc_us-gaap_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities_2EEA7B747BBFCBF0BD4E7A9688B7A313" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:to="loc_us-gaap_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities_2EEA7B747BBFCBF0BD4E7A9688B7A313" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebt" xlink:label="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_A267275EB3AB3FD4B0FE7A9688B7424D" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:to="loc_us-gaap_GainsLossesOnExtinguishmentOfDebt_A267275EB3AB3FD4B0FE7A9688B7424D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncreaseDecreaseInReceivables" xlink:label="loc_us-gaap_IncreaseDecreaseInReceivables_ACB1A0BE720D915CB8CB7A9688B7A218" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:to="loc_us-gaap_IncreaseDecreaseInReceivables_ACB1A0BE720D915CB8CB7A9688B7A218" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncreaseDecreaseInInventories" xlink:label="loc_us-gaap_IncreaseDecreaseInInventories_98B6374D27BFE24F0A6A7A9688B726A8" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:to="loc_us-gaap_IncreaseDecreaseInInventories_98B6374D27BFE24F0A6A7A9688B726A8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:label="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_F396F4227EE6562E34B27A9688B7500A" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:to="loc_us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_F396F4227EE6562E34B27A9688B7500A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:label="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_63C3597186527B47A11D7A9688B765EA" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:to="loc_us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_63C3597186527B47A11D7A9688B765EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherOperatingActivitiesCashFlowStatement" xlink:label="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_472FD89E38D478F05EA77A9688B787EF" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_85ED4CD36A9448ADE4427A9688B49553" xlink:to="loc_us-gaap_OtherOperatingActivitiesCashFlowStatement_472FD89E38D478F05EA77A9688B787EF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_3128FB891B31AB4A75DA7A9688B7F4B7" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_6D5D22D3BACE180957F87A9688AF207D" xlink:to="loc_us-gaap_NetCashProvidedByUsedInOperatingActivities_3128FB891B31AB4A75DA7A9688B7F4B7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_A91E920102294ACC23487A9688B7EE2F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_DD3ADCF87A1CBFDA448A7A9688AFFC38" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_A91E920102294ACC23487A9688B7EE2F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PaymentsToAcquireProductiveAssets" xlink:label="loc_us-gaap_PaymentsToAcquireProductiveAssets_92BC3C8BCFB415C4B25D7A9688B70696" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_A91E920102294ACC23487A9688B7EE2F" xlink:to="loc_us-gaap_PaymentsToAcquireProductiveAssets_92BC3C8BCFB415C4B25D7A9688B70696" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromSalesOfBusinessAffiliateAndProductiveAssets" xlink:label="loc_us-gaap_ProceedsFromSalesOfBusinessAffiliateAndProductiveAssets_EE2DD9D1C4615CE466D47A9688B70662" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_A91E920102294ACC23487A9688B7EE2F" xlink:to="loc_us-gaap_ProceedsFromSalesOfBusinessAffiliateAndProductiveAssets_EE2DD9D1C4615CE466D47A9688B70662" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_317A2B28FA05B3925F4A7A9688B7C024" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_A91E920102294ACC23487A9688B7EE2F" xlink:to="loc_us-gaap_NetCashProvidedByUsedInInvestingActivities_317A2B28FA05B3925F4A7A9688B7C024" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_890BB358E63D67692A127A9688B73F53" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_DD3ADCF87A1CBFDA448A7A9688AFFC38" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_890BB358E63D67692A127A9688B73F53" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromBankDebt" xlink:label="loc_us-gaap_ProceedsFromBankDebt_7FC1805892D4F46A13A87A9688B74F80" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_890BB358E63D67692A127A9688B73F53" xlink:to="loc_us-gaap_ProceedsFromBankDebt_7FC1805892D4F46A13A87A9688B74F80" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RepaymentsOfLongTermDebt" xlink:label="loc_us-gaap_RepaymentsOfLongTermDebt_BA4C47573B46B7DA041A7A9688B7F02E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_890BB358E63D67692A127A9688B73F53" xlink:to="loc_us-gaap_RepaymentsOfLongTermDebt_BA4C47573B46B7DA041A7A9688B7F02E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:label="loc_us-gaap_ProceedsFromLinesOfCredit_3A8E2F60FEF9E2910F477A9688B7C2D3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_890BB358E63D67692A127A9688B73F53" xlink:to="loc_us-gaap_ProceedsFromLinesOfCredit_3A8E2F60FEF9E2910F477A9688B7C2D3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RepaymentsOfLinesOfCredit" xlink:label="loc_us-gaap_RepaymentsOfLinesOfCredit_C5611FA407E10EEB2BC27A9688B77DAF" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_890BB358E63D67692A127A9688B73F53" xlink:to="loc_us-gaap_RepaymentsOfLinesOfCredit_C5611FA407E10EEB2BC27A9688B77DAF" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DeferredPurchasePriceAmountPaidthru2016" xlink:label="loc_trs_DeferredPurchasePriceAmountPaidthru2016_B69F2CCFCEF345F1A00A7A9688B9E56B" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_890BB358E63D67692A127A9688B73F53" xlink:to="loc_trs_DeferredPurchasePriceAmountPaidthru2016_B69F2CCFCEF345F1A00A7A9688B9E56B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PaymentsOfDebtExtinguishmentCosts" xlink:label="loc_us-gaap_PaymentsOfDebtExtinguishmentCosts_269F5131669E8A80B91E7A9688B9AD3F" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_890BB358E63D67692A127A9688B73F53" xlink:to="loc_us-gaap_PaymentsOfDebtExtinguishmentCosts_269F5131669E8A80B91E7A9688B9AD3F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_4AABD0B9A35C1B91ADC77A9688B998C1" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_890BB358E63D67692A127A9688B73F53" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_4AABD0B9A35C1B91ADC77A9688B998C1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromStockOptionsExercised" xlink:label="loc_us-gaap_ProceedsFromStockOptionsExercised_AA266CB4F469399164417A9688B9F6E9" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_890BB358E63D67692A127A9688B73F53" xlink:to="loc_us-gaap_ProceedsFromStockOptionsExercised_AA266CB4F469399164417A9688B9F6E9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromPaymentsForOtherFinancingActivities" xlink:label="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_4726946EC87A7F4FD42E7A9688B9AD17" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_890BB358E63D67692A127A9688B73F53" xlink:to="loc_us-gaap_ProceedsFromPaymentsForOtherFinancingActivities_4726946EC87A7F4FD42E7A9688B9AD17" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivities" xlink:label="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_7FAF0FA055C7FBE7E5E07A9688B9BE5E" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_890BB358E63D67692A127A9688B73F53" xlink:to="loc_us-gaap_NetCashProvidedByUsedInFinancingActivities_7FAF0FA055C7FBE7E5E07A9688B9BE5E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:label="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_B961EDE7E7B560DC25B87A9688BA9972" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_DD3ADCF87A1CBFDA448A7A9688AFFC38" xlink:to="loc_us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease_B961EDE7E7B560DC25B87A9688BA9972" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:label="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_267917CF98F3C4D28C867A9688BAC6CF" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_DD3ADCF87A1CBFDA448A7A9688AFFC38" xlink:to="loc_us-gaap_CashAndCashEquivalentsAtCarryingValue_267917CF98F3C4D28C867A9688BAC6CF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:label="loc_us-gaap_SupplementalCashFlowInformationAbstract_336E03334A4EB7BF06787A9688BADE18" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_DD3ADCF87A1CBFDA448A7A9688AFFC38" xlink:to="loc_us-gaap_SupplementalCashFlowInformationAbstract_336E03334A4EB7BF06787A9688BADE18" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestPaidNet" xlink:label="loc_us-gaap_InterestPaidNet_2145EA02B22F69E23C0E7A9688BAF01C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_336E03334A4EB7BF06787A9688BADE18" xlink:to="loc_us-gaap_InterestPaidNet_2145EA02B22F69E23C0E7A9688BAF01C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeTaxesPaid" xlink:label="loc_us-gaap_IncomeTaxesPaid_FA584C93C9EE79D1C97A7A9688BA24B1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SupplementalCashFlowInformationAbstract_336E03334A4EB7BF06787A9688BADE18" xlink:to="loc_us-gaap_IncomeTaxesPaid_FA584C93C9EE79D1C97A7A9688BA24B1" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/ConsolidatedStatementOfComprehensiveIncome" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_CCA4948E67DA52AABFC5E40B3AC8F2AC" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_D7D66DABF4D35082A0BEFA12DC031114" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_CCA4948E67DA52AABFC5E40B3AC8F2AC" xlink:to="loc_us-gaap_StatementTable_D7D66DABF4D35082A0BEFA12DC031114" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_CDCD7409048F5664A8025FD880D1A495" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_D7D66DABF4D35082A0BEFA12DC031114" xlink:to="loc_us-gaap_StatementScenarioAxis_CDCD7409048F5664A8025FD880D1A495" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_B8822E86337E1E20F946A46654B0E2E9_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_CDCD7409048F5664A8025FD880D1A495" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_B8822E86337E1E20F946A46654B0E2E9_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_113D4A9E84B5544AB5999CB64A7417FA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_CDCD7409048F5664A8025FD880D1A495" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_113D4A9E84B5544AB5999CB64A7417FA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProfitLoss" xlink:label="loc_us-gaap_ProfitLoss_7CAD4A797E1B5B31B344A4731E638C20" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_CCA4948E67DA52AABFC5E40B3AC8F2AC" xlink:to="loc_us-gaap_ProfitLoss_7CAD4A797E1B5B31B344A4731E638C20" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_9C7E949C2EE35D2086383048D8DABF99" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_CCA4948E67DA52AABFC5E40B3AC8F2AC" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_9C7E949C2EE35D2086383048D8DABF99" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax_7CFC5BB87ADE51E89E8BB9FD963F497D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_9C7E949C2EE35D2086383048D8DABF99" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax_7CFC5BB87ADE51E89E8BB9FD963F497D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_6B31C9995E7957CD9416B0D7E58B3330" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_9C7E949C2EE35D2086383048D8DABF99" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_6B31C9995E7957CD9416B0D7E58B3330" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax_273BF468066D53B4BC3CC3BB3BBD2F4D" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_9C7E949C2EE35D2086383048D8DABF99" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax_273BF468066D53B4BC3CC3BB3BBD2F4D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_C23FFAB7ABCD53869CEADABB46E52CB4" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_9C7E949C2EE35D2086383048D8DABF99" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_C23FFAB7ABCD53869CEADABB46E52CB4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_07194FBEC892505EA86A21AC5DC818F2" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_CCA4948E67DA52AABFC5E40B3AC8F2AC" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_07194FBEC892505EA86A21AC5DC818F2" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/ConsolidatedStatementOfIncomeStatement" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_5F22163106CBEF678A5A7A9688ECD605" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_C8AE4E59C7AC729E48E27A9688EBB255" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_5F22163106CBEF678A5A7A9688ECD605" xlink:to="loc_us-gaap_StatementTable_C8AE4E59C7AC729E48E27A9688EBB255" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:label="loc_us-gaap_StatementScenarioAxis_2DC6B37BFE3C293FBEEF7A9688EBB2FC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_C8AE4E59C7AC729E48E27A9688EBB255" xlink:to="loc_us-gaap_StatementScenarioAxis_2DC6B37BFE3C293FBEEF7A9688EBB2FC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_C2F643654502330C8BA97A9688EB8C43_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementScenarioAxis_2DC6B37BFE3C293FBEEF7A9688EBB2FC" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_C2F643654502330C8BA97A9688EB8C43_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:label="loc_us-gaap_ScenarioUnspecifiedDomain_C2F643654502330C8BA97A9688EB8C43" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementScenarioAxis_2DC6B37BFE3C293FBEEF7A9688EBB2FC" xlink:to="loc_us-gaap_ScenarioUnspecifiedDomain_C2F643654502330C8BA97A9688EB8C43" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SalesRevenueNet" xlink:label="loc_us-gaap_SalesRevenueNet_7695D9902209E04024267A9688F1EDAD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5F22163106CBEF678A5A7A9688ECD605" xlink:to="loc_us-gaap_SalesRevenueNet_7695D9902209E04024267A9688F1EDAD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_6C0ADDFE968D4C855A927A9688F119C1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5F22163106CBEF678A5A7A9688ECD605" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_6C0ADDFE968D4C855A927A9688F119C1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GrossProfit" xlink:label="loc_us-gaap_GrossProfit_4EEEF5387A924479EC257A9688F18100" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5F22163106CBEF678A5A7A9688ECD605" xlink:to="loc_us-gaap_GrossProfit_4EEEF5387A924479EC257A9688F18100" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_17A6DF92EC20AAFCF3BA7A9688F157AF" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5F22163106CBEF678A5A7A9688ECD605" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_17A6DF92EC20AAFCF3BA7A9688F157AF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_21FB7047D2E3089997937A9688F31E1A" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5F22163106CBEF678A5A7A9688ECD605" xlink:to="loc_us-gaap_OperatingIncomeLoss_21FB7047D2E3089997937A9688F31E1A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NonoperatingIncomeExpenseAbstract" xlink:label="loc_us-gaap_NonoperatingIncomeExpenseAbstract_3EAA734C28EE44B9EE2E7A9688F3F67D" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5F22163106CBEF678A5A7A9688ECD605" xlink:to="loc_us-gaap_NonoperatingIncomeExpenseAbstract_3EAA734C28EE44B9EE2E7A9688F3F67D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestExpense" xlink:label="loc_us-gaap_InterestExpense_B12EF7A3432EFA609A1B7A9688F3B441" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_3EAA734C28EE44B9EE2E7A9688F3F67D" xlink:to="loc_us-gaap_InterestExpense_B12EF7A3432EFA609A1B7A9688F3B441" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_8532F26576CA0A62EDFF7A9688F32A88" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_3EAA734C28EE44B9EE2E7A9688F3F67D" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_8532F26576CA0A62EDFF7A9688F32A88" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NonoperatingIncomeExpense" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_EB608BD1A3F836BE75287A9688F331AA" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_3EAA734C28EE44B9EE2E7A9688F3F67D" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_EB608BD1A3F836BE75287A9688F331AA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_EAA875B346A13ED921A97A9688F3BF4D" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5F22163106CBEF678A5A7A9688ECD605" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_EAA875B346A13ED921A97A9688F3BF4D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_E6C669D50B9F1F1302397A9688F38BC5" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5F22163106CBEF678A5A7A9688ECD605" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_E6C669D50B9F1F1302397A9688F38BC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_771E338C9DA9086EB2777A9688F32FA2" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5F22163106CBEF678A5A7A9688ECD605" xlink:to="loc_us-gaap_NetIncomeLoss_771E338C9DA9086EB2777A9688F32FA2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EarningsPerShareBasicAbstract" xlink:label="loc_us-gaap_EarningsPerShareBasicAbstract_6482D689DD9A952D87A27A9688F358B9" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5F22163106CBEF678A5A7A9688ECD605" xlink:to="loc_us-gaap_EarningsPerShareBasicAbstract_6482D689DD9A952D87A27A9688F358B9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EarningsPerShareBasic" xlink:label="loc_us-gaap_EarningsPerShareBasic_8B37EA9B7A3D31E7A38C7A9688F303C9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_6482D689DD9A952D87A27A9688F358B9" xlink:to="loc_us-gaap_EarningsPerShareBasic_8B37EA9B7A3D31E7A38C7A9688F303C9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_AD54E974594C4367E39B7A9688F4EF01" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_6482D689DD9A952D87A27A9688F358B9" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_AD54E974594C4367E39B7A9688F4EF01" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EarningsPerShareDilutedAbstract" xlink:label="loc_us-gaap_EarningsPerShareDilutedAbstract_ADA92269042CAE24FA9F7A9688F4A912" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_5F22163106CBEF678A5A7A9688ECD605" xlink:to="loc_us-gaap_EarningsPerShareDilutedAbstract_ADA92269042CAE24FA9F7A9688F4A912" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EarningsPerShareDiluted" xlink:label="loc_us-gaap_EarningsPerShareDiluted_A00D1E2810A48E1E5BA67A9688F40B8A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_ADA92269042CAE24FA9F7A9688F4A912" xlink:to="loc_us-gaap_EarningsPerShareDiluted_A00D1E2810A48E1E5BA67A9688F40B8A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_360B2C428F43EB302BC17A9688F42256" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_ADA92269042CAE24FA9F7A9688F4A912" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_360B2C428F43EB302BC17A9688F42256" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/ConsolidatedStatementOfShareholdersEquityStatement" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementLineItems" xlink:label="loc_us-gaap_StatementLineItems_D2C7935B180F5F05AA90D295B3BE52D4" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementTable" xlink:label="loc_us-gaap_StatementTable_702C760304CC5107B3FCABB97CAEFD2F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_D2C7935B180F5F05AA90D295B3BE52D4" xlink:to="loc_us-gaap_StatementTable_702C760304CC5107B3FCABB97CAEFD2F" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_3B153297345153B59C43D74926C273F7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_702C760304CC5107B3FCABB97CAEFD2F" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_3B153297345153B59C43D74926C273F7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_6BBA051810455166CA34A03766400E90_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_3B153297345153B59C43D74926C273F7" xlink:to="loc_us-gaap_EquityComponentDomain_6BBA051810455166CA34A03766400E90_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityComponentDomain" xlink:label="loc_us-gaap_EquityComponentDomain_3ED3D01A190550FE9308A9A0712B0C37" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_3B153297345153B59C43D74926C273F7" xlink:to="loc_us-gaap_EquityComponentDomain_3ED3D01A190550FE9308A9A0712B0C37" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_CD82F76C8A9B5D4AA19848AC371E8834" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_3ED3D01A190550FE9308A9A0712B0C37" xlink:to="loc_us-gaap_CommonStockMember_CD82F76C8A9B5D4AA19848AC371E8834" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_84EB75E36FED5EB59A8600A39F5B23D2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_3ED3D01A190550FE9308A9A0712B0C37" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_84EB75E36FED5EB59A8600A39F5B23D2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:label="loc_us-gaap_RetainedEarningsMember_4CE0B853B8755EFDB1652892266EF596" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_3ED3D01A190550FE9308A9A0712B0C37" xlink:to="loc_us-gaap_RetainedEarningsMember_4CE0B853B8755EFDB1652892266EF596" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_B9B63EAB62B35753A3FF8BEE9D828A96" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_3ED3D01A190550FE9308A9A0712B0C37" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_B9B63EAB62B35753A3FF8BEE9D828A96" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_DDA7636C94105D3DA344EF6F3C7F7096" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D2C7935B180F5F05AA90D295B3BE52D4" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_DDA7636C94105D3DA344EF6F3C7F7096" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NetIncomeLoss" xlink:label="loc_us-gaap_NetIncomeLoss_332F3E9AE34D518F9B2FDE9E3A10B85F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D2C7935B180F5F05AA90D295B3BE52D4" xlink:to="loc_us-gaap_NetIncomeLoss_332F3E9AE34D518F9B2FDE9E3A10B85F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_ADDA79A895835A7695B491AA8FE59862" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D2C7935B180F5F05AA90D295B3BE52D4" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_ADDA79A895835A7695B491AA8FE59862" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation" xlink:label="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_2D6BBB3FF19D56798D5E4379BC70FAF3" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D2C7935B180F5F05AA90D295B3BE52D4" xlink:to="loc_us-gaap_PaymentsRelatedToTaxWithholdingForShareBasedCompensation_2D6BBB3FF19D56798D5E4379BC70FAF3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_5301096786F95EDA9F05287B91AA3667" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_D2C7935B180F5F05AA90D295B3BE52D4" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_5301096786F95EDA9F05287B91AA3667" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DefinedBenefitPlans" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DefinedBenefitPlansDefinedBenefitPlansNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C615A856D5E0A706CC72C0DDC0F017CA" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_3D624C20714C13E76F0CC0DDC0F07830" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C615A856D5E0A706CC72C0DDC0F017CA" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_3D624C20714C13E76F0CC0DDC0F07830" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis" xlink:label="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_376C5FC41F2313CF116FC0DDC0F0D169" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_3D624C20714C13E76F0CC0DDC0F07830" xlink:to="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_376C5FC41F2313CF116FC0DDC0F0D169" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_C767F7DB5644118DED73C0DDC0F0D05D_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_376C5FC41F2313CF116FC0DDC0F0D169" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_C767F7DB5644118DED73C0DDC0F0D05D_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_C767F7DB5644118DED73C0DDC0F0D05D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_376C5FC41F2313CF116FC0DDC0F0D169" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_C767F7DB5644118DED73C0DDC0F0D05D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_FB9253BDE5005687DE99C0DDC0F09AEA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansDomain_C767F7DB5644118DED73C0DDC0F0D05D" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_FB9253BDE5005687DE99C0DDC0F09AEA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_A33FD40F9FC808F25BDDC0DDC0F00407" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansDomain_C767F7DB5644118DED73C0DDC0F0D05D" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_A33FD40F9FC808F25BDDC0DDC0F00407" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1" xlink:label="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1_CCEF9032DB110AC83E7DC0DDC0F00FC0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C615A856D5E0A706CC72C0DDC0F017CA" xlink:to="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1_CCEF9032DB110AC83E7DC0DDC0F00FC0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer" xlink:label="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_5345E75148816DA1B2CFC0DDC0F0F34E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C615A856D5E0A706CC72C0DDC0F017CA" xlink:to="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_5345E75148816DA1B2CFC0DDC0F0F34E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansEstimatedFutureEmployerContributionsInCurrentFiscalYear" xlink:label="loc_us-gaap_DefinedBenefitPlansEstimatedFutureEmployerContributionsInCurrentFiscalYear_D57D4E1CAEB97367885CC0DDC0F0B455" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_C615A856D5E0A706CC72C0DDC0F017CA" xlink:to="loc_us-gaap_DefinedBenefitPlansEstimatedFutureEmployerContributionsInCurrentFiscalYear_D57D4E1CAEB97367885CC0DDC0F0B455" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DefinedBenefitPlansNetPeriodicPensionAndPostretirementBenefitCostsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_9701C2043B4F5D53B42954C102294C87" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable" xlink:label="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_FE77DC30FAB85172B57EB804357F2D36" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_9701C2043B4F5D53B42954C102294C87" xlink:to="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_FE77DC30FAB85172B57EB804357F2D36" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis" xlink:label="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_14FBDA1FA5C55F35A49AD7E432A259BF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansDisclosuresTable_FE77DC30FAB85172B57EB804357F2D36" xlink:to="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_14FBDA1FA5C55F35A49AD7E432A259BF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_2C11DDD775A45E86D844A466557AE687_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_14FBDA1FA5C55F35A49AD7E432A259BF" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_2C11DDD775A45E86D844A466557AE687_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlansDomain" xlink:label="loc_us-gaap_DefinedBenefitPlansDomain_D7315166842D5BFCB587DA4B663049F4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis_14FBDA1FA5C55F35A49AD7E432A259BF" xlink:to="loc_us-gaap_DefinedBenefitPlansDomain_D7315166842D5BFCB587DA4B663049F4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_874A13E49D285A6A9452141C1268869D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansDomain_D7315166842D5BFCB587DA4B663049F4" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_874A13E49D285A6A9452141C1268869D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_A3AA1B11A175532782924FD902E32F39" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansDomain_D7315166842D5BFCB587DA4B663049F4" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_A3AA1B11A175532782924FD902E32F39" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_D03140364DF655FE9BD29D03B1D45A56" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_9701C2043B4F5D53B42954C102294C87" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_D03140364DF655FE9BD29D03B1D45A56" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_AE886AB7E3C950B59B99CECBDF685E7B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_9701C2043B4F5D53B42954C102294C87" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_AE886AB7E3C950B59B99CECBDF685E7B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_7A927C07C7425398A273263B027516D7" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_9701C2043B4F5D53B42954C102294C87" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_7A927C07C7425398A273263B027516D7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_B70ABA1DAD535A538CE31B83C7956DB8" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_9701C2043B4F5D53B42954C102294C87" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfPriorServiceCostCredit_B70ABA1DAD535A538CE31B83C7956DB8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1" xlink:label="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1_2F8429D018315F4FB56DCCD0C3F6C22A" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_9701C2043B4F5D53B42954C102294C87" xlink:to="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1_2F8429D018315F4FB56DCCD0C3F6C22A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_9874AA6511175EB7AC80451FFD3DB20C" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_9701C2043B4F5D53B42954C102294C87" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_9874AA6511175EB7AC80451FFD3DB20C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_F5FFF52E6E475009A6B6099979D3120D" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTableTextBlockLineItems_9701C2043B4F5D53B42954C102294C87" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_F5FFF52E6E475009A6B6099979D3120D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DefinedBenefitPlansTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DerivativeInstruments" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DerivativeInstrumentsDerivativeNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeLineItems" xlink:label="loc_us-gaap_DerivativeLineItems_D3E603888AC6568C8802A91784BB93B7" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeTable" xlink:label="loc_us-gaap_DerivativeTable_C6DB64A5A8EF55FDAE50850D96512522" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_D3E603888AC6568C8802A91784BB93B7" xlink:to="loc_us-gaap_DerivativeTable_C6DB64A5A8EF55FDAE50850D96512522" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_1F5B8A33C6BA5B1181627B63F7D19E15" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_C6DB64A5A8EF55FDAE50850D96512522" xlink:to="loc_us-gaap_RangeAxis_1F5B8A33C6BA5B1181627B63F7D19E15" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_FE81E8DC43F3ADF9CF83A5814A56A3CA_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_1F5B8A33C6BA5B1181627B63F7D19E15" xlink:to="loc_us-gaap_RangeMember_FE81E8DC43F3ADF9CF83A5814A56A3CA_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_8F1EE2D2449C5D529652FBBADC9B1A37" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_1F5B8A33C6BA5B1181627B63F7D19E15" xlink:to="loc_us-gaap_RangeMember_8F1EE2D2449C5D529652FBBADC9B1A37" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_FE2FEB01D7995878A10DCCDAE4DD4EE0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_8F1EE2D2449C5D529652FBBADC9B1A37" xlink:to="loc_us-gaap_MaximumMember_FE2FEB01D7995878A10DCCDAE4DD4EE0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_2FAD857E462B52BC96BB648EB8E28EEF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_8F1EE2D2449C5D529652FBBADC9B1A37" xlink:to="loc_us-gaap_MinimumMember_2FAD857E462B52BC96BB648EB8E28EEF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_88D1F9C0AA535651A3A152CAE7A50263" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_C6DB64A5A8EF55FDAE50850D96512522" xlink:to="loc_us-gaap_DebtInstrumentAxis_88D1F9C0AA535651A3A152CAE7A50263" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_B77AB1A0F2915998C6FEA5814A561505_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_88D1F9C0AA535651A3A152CAE7A50263" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_B77AB1A0F2915998C6FEA5814A561505_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_7BC9F1262F34551B9F0C82FF577275CD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_88D1F9C0AA535651A3A152CAE7A50263" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_7BC9F1262F34551B9F0C82FF577275CD" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_SeniorSecuredTermLoanMember" xlink:label="loc_trs_SeniorSecuredTermLoanMember_DCB354B7CE555CF385F70636362DF201" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7BC9F1262F34551B9F0C82FF577275CD" xlink:to="loc_trs_SeniorSecuredTermLoanMember_DCB354B7CE555CF385F70636362DF201" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_321591BCD8D3545F9BA376460820C74B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_C6DB64A5A8EF55FDAE50850D96512522" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_321591BCD8D3545F9BA376460820C74B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_FADECE876DFB784BAA46A5814A562214_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_321591BCD8D3545F9BA376460820C74B" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_FADECE876DFB784BAA46A5814A562214_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_1A3FB9D1B15E5C4C842BCCEE51156C37" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_321591BCD8D3545F9BA376460820C74B" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_1A3FB9D1B15E5C4C842BCCEE51156C37" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ForeignExchangeContractMember" xlink:label="loc_us-gaap_ForeignExchangeContractMember_4E16F93077F059BC9308FD53DAF50E7D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_1A3FB9D1B15E5C4C842BCCEE51156C37" xlink:to="loc_us-gaap_ForeignExchangeContractMember_4E16F93077F059BC9308FD53DAF50E7D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_02D8973476005E77B222C30FF4C33B5C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_1A3FB9D1B15E5C4C842BCCEE51156C37" xlink:to="loc_us-gaap_InterestRateSwapMember_02D8973476005E77B222C30FF4C33B5C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_C44FB5A09BAF57BBACDDE3A520225273" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_C6DB64A5A8EF55FDAE50850D96512522" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_C44FB5A09BAF57BBACDDE3A520225273" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_F2F9FC677C95B7387ECFA5814A567E2C_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_C44FB5A09BAF57BBACDDE3A520225273" xlink:to="loc_us-gaap_HedgingRelationshipDomain_F2F9FC677C95B7387ECFA5814A567E2C_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_93A6C4252A0F501D9D216F6EDEBE397A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_C44FB5A09BAF57BBACDDE3A520225273" xlink:to="loc_us-gaap_HedgingRelationshipDomain_93A6C4252A0F501D9D216F6EDEBE397A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CashFlowHedgingMember" xlink:label="loc_us-gaap_CashFlowHedgingMember_F9F04AC1FCB95B479017228BB55CDD94" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_93A6C4252A0F501D9D216F6EDEBE397A" xlink:to="loc_us-gaap_CashFlowHedgingMember_F9F04AC1FCB95B479017228BB55CDD94" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DerivativeMaturityDateAxis" xlink:label="loc_trs_DerivativeMaturityDateAxis_8072689E5AC6514B9EDFB90B98A0A30A" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_C6DB64A5A8EF55FDAE50850D96512522" xlink:to="loc_trs_DerivativeMaturityDateAxis_8072689E5AC6514B9EDFB90B98A0A30A" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DerivativeMaturityDateDomain" xlink:label="loc_trs_DerivativeMaturityDateDomain_315F058573CCE786A10BA5814A56E33D_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_DerivativeMaturityDateAxis_8072689E5AC6514B9EDFB90B98A0A30A" xlink:to="loc_trs_DerivativeMaturityDateDomain_315F058573CCE786A10BA5814A56E33D_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DerivativeMaturityDateDomain" xlink:label="loc_trs_DerivativeMaturityDateDomain_107FA1ED7E0955C480A2CA63C93B5B4E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_DerivativeMaturityDateAxis_8072689E5AC6514B9EDFB90B98A0A30A" xlink:to="loc_trs_DerivativeMaturityDateDomain_107FA1ED7E0955C480A2CA63C93B5B4E" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DerivativeJune2020MaturityMember" xlink:label="loc_trs_DerivativeJune2020MaturityMember_3C488CB8F75A53F595A9552910F532F0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DerivativeMaturityDateDomain_107FA1ED7E0955C480A2CA63C93B5B4E" xlink:to="loc_trs_DerivativeJune2020MaturityMember_3C488CB8F75A53F595A9552910F532F0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_360504A6B01B5EDFAED9DCB7294B1C42" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_D3E603888AC6568C8802A91784BB93B7" xlink:to="loc_invest_DerivativeNotionalAmount_360504A6B01B5EDFAED9DCB7294B1C42" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeFixedInterestRate" xlink:label="loc_us-gaap_DerivativeFixedInterestRate_B2298002969556E3B909CB9F3AE70F6C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_D3E603888AC6568C8802A91784BB93B7" xlink:to="loc_us-gaap_DerivativeFixedInterestRate_B2298002969556E3B909CB9F3AE70F6C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeMaturityDates" xlink:label="loc_us-gaap_DerivativeMaturityDates_13B8BF22793F5CD88FCA192D7C13D14D" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_D3E603888AC6568C8802A91784BB93B7" xlink:to="loc_us-gaap_DerivativeMaturityDates_13B8BF22793F5CD88FCA192D7C13D14D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DerivativeInstrumentsDesignatedAsHedgingFinancialPerformanceDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_6FD3FEBB986957FCB84E68F4A082773D" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_AF54D7E9692C5B2CBD16B8C1FD7179D6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_6FD3FEBB986957FCB84E68F4A082773D" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_AF54D7E9692C5B2CBD16B8C1FD7179D6" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:label="loc_us-gaap_DisposalGroupClassificationAxis_AA849663C0BD5D1DAE8688BF43A2996E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_AF54D7E9692C5B2CBD16B8C1FD7179D6" xlink:to="loc_us-gaap_DisposalGroupClassificationAxis_AA849663C0BD5D1DAE8688BF43A2996E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_4DB0840DC3B3362676C0A4665600CAAB_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_AA849663C0BD5D1DAE8688BF43A2996E" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_4DB0840DC3B3362676C0A4665600CAAB_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:label="loc_us-gaap_DisposalGroupClassificationDomain_059F78AB5CF55ACC960495E9131E369C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DisposalGroupClassificationAxis_AA849663C0BD5D1DAE8688BF43A2996E" xlink:to="loc_us-gaap_DisposalGroupClassificationDomain_059F78AB5CF55ACC960495E9131E369C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DiscontinuedOperationsDisposedOfByMeansOtherThanSaleSpinoffMember" xlink:label="loc_us-gaap_DiscontinuedOperationsDisposedOfByMeansOtherThanSaleSpinoffMember_16591DA764DB51DC9B9113CA83DAC6DC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisposalGroupClassificationDomain_059F78AB5CF55ACC960495E9131E369C" xlink:to="loc_us-gaap_DiscontinuedOperationsDisposedOfByMeansOtherThanSaleSpinoffMember_16591DA764DB51DC9B9113CA83DAC6DC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_425A9C87DF6554BEA2B91B1375610772" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_AF54D7E9692C5B2CBD16B8C1FD7179D6" xlink:to="loc_us-gaap_HedgingDesignationAxis_425A9C87DF6554BEA2B91B1375610772" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_0D925A75DDAE559AC460A46656019AD2_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_425A9C87DF6554BEA2B91B1375610772" xlink:to="loc_us-gaap_HedgingDesignationDomain_0D925A75DDAE559AC460A46656019AD2_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_D1055A761CAC57848D944BF34D7C25FC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_425A9C87DF6554BEA2B91B1375610772" xlink:to="loc_us-gaap_HedgingDesignationDomain_D1055A761CAC57848D944BF34D7C25FC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_56EBA3E7A9C75C148E504740465BA112" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_D1055A761CAC57848D944BF34D7C25FC" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_56EBA3E7A9C75C148E504740465BA112" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_7A08DEFEE9975CD7ACA45DC86CD18FE3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_AF54D7E9692C5B2CBD16B8C1FD7179D6" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_7A08DEFEE9975CD7ACA45DC86CD18FE3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_52A491C844C8107E2E81A466560303D1_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_7A08DEFEE9975CD7ACA45DC86CD18FE3" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_52A491C844C8107E2E81A466560303D1_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_2D76AA2F04705CA0B6FF5D6BB9C79FA9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_7A08DEFEE9975CD7ACA45DC86CD18FE3" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_2D76AA2F04705CA0B6FF5D6BB9C79FA9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_AD685CC6E7CF5E2387802BF446BA344E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_2D76AA2F04705CA0B6FF5D6BB9C79FA9" xlink:to="loc_us-gaap_InterestRateSwapMember_AD685CC6E7CF5E2387802BF446BA344E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ForeignExchangeContractMember" xlink:label="loc_us-gaap_ForeignExchangeContractMember_91F9B1F39CE95EA18C8E9537A8966F92" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_2D76AA2F04705CA0B6FF5D6BB9C79FA9" xlink:to="loc_us-gaap_ForeignExchangeContractMember_91F9B1F39CE95EA18C8E9537A8966F92" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_99EC4639051F5983843C031A1D285E9D" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_AF54D7E9692C5B2CBD16B8C1FD7179D6" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_99EC4639051F5983843C031A1D285E9D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_FAB12509C3D99CDAF9BFA4665603A328_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_99EC4639051F5983843C031A1D285E9D" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_FAB12509C3D99CDAF9BFA4665603A328_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_DDD566C741675818A94DB59AFC5A41CF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_99EC4639051F5983843C031A1D285E9D" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_DDD566C741675818A94DB59AFC5A41CF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestExpenseMember" xlink:label="loc_us-gaap_InterestExpenseMember_34C4E1EA27B8546E89929724780966FA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_DDD566C741675818A94DB59AFC5A41CF" xlink:to="loc_us-gaap_InterestExpenseMember_34C4E1EA27B8546E89929724780966FA" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_IncomelossfromdiscontinuedoperationsnetoftaxMember" xlink:label="loc_trs_IncomelossfromdiscontinuedoperationsnetoftaxMember_0214294BA0FA5887823A9E53B3414A66" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_DDD566C741675818A94DB59AFC5A41CF" xlink:to="loc_trs_IncomelossfromdiscontinuedoperationsnetoftaxMember_0214294BA0FA5887823A9E53B3414A66" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CostOfSalesMember" xlink:label="loc_us-gaap_CostOfSalesMember_C4CCA36A422B5483B6701281A4E91AF7" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_DDD566C741675818A94DB59AFC5A41CF" xlink:to="loc_us-gaap_CostOfSalesMember_C4CCA36A422B5483B6701281A4E91AF7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax_30D41E2C5B71514FAA752E8B5C9AB7C1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_6FD3FEBB986957FCB84E68F4A082773D" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInNetGainLossFromCashFlowHedgesEffectNetOfTax_30D41E2C5B71514FAA752E8B5C9AB7C1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_3F960F0929BA5C97A1CC8BC989E8D5A0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_6FD3FEBB986957FCB84E68F4A082773D" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet_3F960F0929BA5C97A1CC8BC989E8D5A0" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DerivativeInstrumentsDesignatedAsHedgingFinancialPerformanceNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_9DFC357FB16D5C5DA072FA63FE968CA7" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_842D6F5967C155A5A175C1FAE38B000A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_9DFC357FB16D5C5DA072FA63FE968CA7" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_842D6F5967C155A5A175C1FAE38B000A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_8DB84B643B0A54D59BD9DA870851ED3C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_842D6F5967C155A5A175C1FAE38B000A" xlink:to="loc_us-gaap_HedgingDesignationAxis_8DB84B643B0A54D59BD9DA870851ED3C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_5E4D061A3F697F6268B3A46656ADBE0F_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_8DB84B643B0A54D59BD9DA870851ED3C" xlink:to="loc_us-gaap_HedgingDesignationDomain_5E4D061A3F697F6268B3A46656ADBE0F_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_5AA0B3FC8D70504B878A6E8CE01E884F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_8DB84B643B0A54D59BD9DA870851ED3C" xlink:to="loc_us-gaap_HedgingDesignationDomain_5AA0B3FC8D70504B878A6E8CE01E884F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_C2B18DEB0D2155149AE747A506CB9F8C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_5AA0B3FC8D70504B878A6E8CE01E884F" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_C2B18DEB0D2155149AE747A506CB9F8C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_A45C8BDE08B2563CAAD26990AD89F7EF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_842D6F5967C155A5A175C1FAE38B000A" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_A45C8BDE08B2563CAAD26990AD89F7EF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_1B38076A5B3986218DFBA46656B37673_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_A45C8BDE08B2563CAAD26990AD89F7EF" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_1B38076A5B3986218DFBA46656B37673_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_E89AD75A6EAD57E1BBD8A2D393609B74" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_A45C8BDE08B2563CAAD26990AD89F7EF" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_E89AD75A6EAD57E1BBD8A2D393609B74" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestExpenseMember" xlink:label="loc_us-gaap_InterestExpenseMember_9CCB550CE3B55E539F9D9A3391505CBA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_E89AD75A6EAD57E1BBD8A2D393609B74" xlink:to="loc_us-gaap_InterestExpenseMember_9CCB550CE3B55E539F9D9A3391505CBA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_61D43D42C5C95DE98D70141B00C9CBE4" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_842D6F5967C155A5A175C1FAE38B000A" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_61D43D42C5C95DE98D70141B00C9CBE4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_D6AEAFD19D41CD2E9E54A46656B5BC75_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_61D43D42C5C95DE98D70141B00C9CBE4" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_D6AEAFD19D41CD2E9E54A46656B5BC75_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_9B58DE265B7653AA9FBA3F54B57AEBF5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_61D43D42C5C95DE98D70141B00C9CBE4" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_9B58DE265B7653AA9FBA3F54B57AEBF5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_DD8232B79174542B9A5E7A7F0F6FB0F5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_9B58DE265B7653AA9FBA3F54B57AEBF5" xlink:to="loc_us-gaap_InterestRateSwapMember_DD8232B79174542B9A5E7A7F0F6FB0F5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ForeignExchangeContractMember" xlink:label="loc_us-gaap_ForeignExchangeContractMember_682C483C4DED51FE8D234CCAFE3174EF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_9B58DE265B7653AA9FBA3F54B57AEBF5" xlink:to="loc_us-gaap_ForeignExchangeContractMember_682C483C4DED51FE8D234CCAFE3174EF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimateOfTimeToTransfer1" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimateOfTimeToTransfer1_B6AB191663F75314AF333263C195DC37" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_9DFC357FB16D5C5DA072FA63FE968CA7" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimateOfTimeToTransfer1_B6AB191663F75314AF333263C195DC37" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred_AE94A7501CA758BF865848882E91CB46" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_9DFC357FB16D5C5DA072FA63FE968CA7" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred_AE94A7501CA758BF865848882E91CB46" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DerivativeInstrumentsDesignatedAsHedgingFinancialPositionDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativesFairValueLineItems" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_04F8BEC9E1C25120B14DFB5CCE1D9A53" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_4552C4A5283F56FBB26573B4E48B3D4E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_04F8BEC9E1C25120B14DFB5CCE1D9A53" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_4552C4A5283F56FBB26573B4E48B3D4E" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_3608CAD978EB56E59E8553269772FDB0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_4552C4A5283F56FBB26573B4E48B3D4E" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_3608CAD978EB56E59E8553269772FDB0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_DAA50788BED0AFF87C40D29BA90CDE81_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_3608CAD978EB56E59E8553269772FDB0" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_DAA50788BED0AFF87C40D29BA90CDE81_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_B656DB544868548CA0C9F126E49ABB8C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_3608CAD978EB56E59E8553269772FDB0" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_B656DB544868548CA0C9F126E49ABB8C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestExpenseMember" xlink:label="loc_us-gaap_InterestExpenseMember_6FEE166E86615081A5C33C67E2CCDD16" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_B656DB544868548CA0C9F126E49ABB8C" xlink:to="loc_us-gaap_InterestExpenseMember_6FEE166E86615081A5C33C67E2CCDD16" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_04A150599C13521E9C2A85EE52704655" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_4552C4A5283F56FBB26573B4E48B3D4E" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_04A150599C13521E9C2A85EE52704655" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_E9D40BA0877368D5368FD29BA90C571D_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_04A150599C13521E9C2A85EE52704655" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_E9D40BA0877368D5368FD29BA90C571D_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_BB90FEA644F85D2085858400880E9C74" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_04A150599C13521E9C2A85EE52704655" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_BB90FEA644F85D2085858400880E9C74" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_15AEED2626F75AAA96DDE4CFA527E451" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_BB90FEA644F85D2085858400880E9C74" xlink:to="loc_us-gaap_InterestRateSwapMember_15AEED2626F75AAA96DDE4CFA527E451" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ForeignExchangeContractMember" xlink:label="loc_us-gaap_ForeignExchangeContractMember_E924092EAE0754C8807CCAE5CA2CB4DD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_BB90FEA644F85D2085858400880E9C74" xlink:to="loc_us-gaap_ForeignExchangeContractMember_E924092EAE0754C8807CCAE5CA2CB4DD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:label="loc_us-gaap_HedgingDesignationAxis_EFD6754A9539564B8E884A3DEF26F513" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_4552C4A5283F56FBB26573B4E48B3D4E" xlink:to="loc_us-gaap_HedgingDesignationAxis_EFD6754A9539564B8E884A3DEF26F513" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_1E6065E97C2AD1F42828D29BA90CE09C_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_EFD6754A9539564B8E884A3DEF26F513" xlink:to="loc_us-gaap_HedgingDesignationDomain_1E6065E97C2AD1F42828D29BA90CE09C_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:label="loc_us-gaap_HedgingDesignationDomain_47DC74AA6E8257CF9AA671A297EEB5FE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_EFD6754A9539564B8E884A3DEF26F513" xlink:to="loc_us-gaap_HedgingDesignationDomain_47DC74AA6E8257CF9AA671A297EEB5FE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_229A25DFF4775D0DBA536ED69C7F7A1D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_47DC74AA6E8257CF9AA671A297EEB5FE" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_229A25DFF4775D0DBA536ED69C7F7A1D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_B2CAFABF9CA65FFD973360446BC52748" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_4552C4A5283F56FBB26573B4E48B3D4E" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_B2CAFABF9CA65FFD973360446BC52748" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_79A2285B54F5D8040C1DD29BA90C3965_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_B2CAFABF9CA65FFD973360446BC52748" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_79A2285B54F5D8040C1DD29BA90C3965_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_FE1658CF2803573A9202962FD4225938" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_B2CAFABF9CA65FFD973360446BC52748" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_FE1658CF2803573A9202962FD4225938" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember" xlink:label="loc_us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember_88734CD5D1D65B7BAB1E27B66B485E7C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_FE1658CF2803573A9202962FD4225938" xlink:to="loc_us-gaap_PrepaidExpensesAndOtherCurrentAssetsMember_88734CD5D1D65B7BAB1E27B66B485E7C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherAssetsMember" xlink:label="loc_us-gaap_OtherAssetsMember_894FCA62E8DE5F65966E254EF7B01355" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_FE1658CF2803573A9202962FD4225938" xlink:to="loc_us-gaap_OtherAssetsMember_894FCA62E8DE5F65966E254EF7B01355" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccruedLiabilitiesMember" xlink:label="loc_us-gaap_AccruedLiabilitiesMember_34445FF126B1508D98AFFA81BB022594" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_FE1658CF2803573A9202962FD4225938" xlink:to="loc_us-gaap_AccruedLiabilitiesMember_34445FF126B1508D98AFFA81BB022594" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherLiabilitiesMember" xlink:label="loc_us-gaap_OtherLiabilitiesMember_668FEA923A3A516C8937E5CDA84C63BC" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_FE1658CF2803573A9202962FD4225938" xlink:to="loc_us-gaap_OtherLiabilitiesMember_668FEA923A3A516C8937E5CDA84C63BC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral_BA567E1C08DB59AEB3D1A5878330DCCB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_04F8BEC9E1C25120B14DFB5CCE1D9A53" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral_BA567E1C08DB59AEB3D1A5878330DCCB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral_A6C31EA9371A5E72A322D667C52ACA1E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_04F8BEC9E1C25120B14DFB5CCE1D9A53" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral_A6C31EA9371A5E72A322D667C52ACA1E" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DerivativeInstrumentsFairValueMeasurementsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_14B269DDCB965FB68C49FBB4FD57D456" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_2B17685D4E525E48AEE5AD2F7F52AE85" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_14B269DDCB965FB68C49FBB4FD57D456" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_2B17685D4E525E48AEE5AD2F7F52AE85" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FinancialInstrumentAxis" xlink:label="loc_us-gaap_FinancialInstrumentAxis_AE670D8E5F4C5F46AD8C5C66E6FFAF45" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_2B17685D4E525E48AEE5AD2F7F52AE85" xlink:to="loc_us-gaap_FinancialInstrumentAxis_AE670D8E5F4C5F46AD8C5C66E6FFAF45" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_2CB3A8678F5EFFEFBE23A46655D2E030_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_AE670D8E5F4C5F46AD8C5C66E6FFAF45" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_2CB3A8678F5EFFEFBE23A46655D2E030_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_6345FD46FF29577E9C19C2193F92C457" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_AE670D8E5F4C5F46AD8C5C66E6FFAF45" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_6345FD46FF29577E9C19C2193F92C457" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_1B4EAFC0D8F95FA687F86AFDF1BF8BCE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_6345FD46FF29577E9C19C2193F92C457" xlink:to="loc_us-gaap_InterestRateSwapMember_1B4EAFC0D8F95FA687F86AFDF1BF8BCE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ForeignExchangeContractMember" xlink:label="loc_us-gaap_ForeignExchangeContractMember_39A5B96C8EF15A86B74F988B68E3B600" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_6345FD46FF29577E9C19C2193F92C457" xlink:to="loc_us-gaap_ForeignExchangeContractMember_39A5B96C8EF15A86B74F988B68E3B600" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:label="loc_us-gaap_FairValueByMeasurementFrequencyAxis_CC6AB444C3DC501DB739A319DEDD3635" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_2B17685D4E525E48AEE5AD2F7F52AE85" xlink:to="loc_us-gaap_FairValueByMeasurementFrequencyAxis_CC6AB444C3DC501DB739A319DEDD3635" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_A4C84C42A80FF0E1C8BFA46655D2E50E_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_CC6AB444C3DC501DB739A319DEDD3635" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_A4C84C42A80FF0E1C8BFA46655D2E50E_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:label="loc_us-gaap_FairValueMeasurementFrequencyDomain_84778E47691959F5A2D016F9972A4468" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementFrequencyAxis_CC6AB444C3DC501DB739A319DEDD3635" xlink:to="loc_us-gaap_FairValueMeasurementFrequencyDomain_84778E47691959F5A2D016F9972A4468" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_102C1154FCAA5AAB8EE64E70A3785C7D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementFrequencyDomain_84778E47691959F5A2D016F9972A4468" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_102C1154FCAA5AAB8EE64E70A3785C7D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_CF6201216E97564B84B989E516EC0D3D" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_2B17685D4E525E48AEE5AD2F7F52AE85" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_CF6201216E97564B84B989E516EC0D3D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_5DF2CAB92052BCF43D8BA46655D2D696_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_CF6201216E97564B84B989E516EC0D3D" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_5DF2CAB92052BCF43D8BA46655D2D696_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_D759C594DB5A5C659D7392009CB2DE9C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_CF6201216E97564B84B989E516EC0D3D" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_D759C594DB5A5C659D7392009CB2DE9C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_0E1A7799C99A5F31AEBF30205879AC2C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_D759C594DB5A5C659D7392009CB2DE9C" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_0E1A7799C99A5F31AEBF30205879AC2C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_81C29802EA2D5FEC8EA9CAD83771DA8B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_D759C594DB5A5C659D7392009CB2DE9C" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_81C29802EA2D5FEC8EA9CAD83771DA8B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_8902644424E958E08C38845DE62CF59C" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_D759C594DB5A5C659D7392009CB2DE9C" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_8902644424E958E08C38845DE62CF59C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeAssets" xlink:label="loc_us-gaap_DerivativeAssets_11D4C2F64BEA553CA6C27EDA4381D2D9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_14B269DDCB965FB68C49FBB4FD57D456" xlink:to="loc_us-gaap_DerivativeAssets_11D4C2F64BEA553CA6C27EDA4381D2D9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:label="loc_us-gaap_DerivativeLiabilities_CEC58ED13BCF5505B859F56F8FE637FE" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_14B269DDCB965FB68C49FBB4FD57D456" xlink:to="loc_us-gaap_DerivativeLiabilities_CEC58ED13BCF5505B859F56F8FE637FE" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DerivativeInstrumentsTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_06B8C10A71C050139B72D084EB27F855" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_9034D97225B15330901FC3F7D8BE4145" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_06B8C10A71C050139B72D084EB27F855" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_9034D97225B15330901FC3F7D8BE4145" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_81DB399824D4503785BC585DFD99791F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_9034D97225B15330901FC3F7D8BE4145" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_81DB399824D4503785BC585DFD99791F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_6BAB6C81C7ED21550846A46654363EFD_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_81DB399824D4503785BC585DFD99791F" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_6BAB6C81C7ED21550846A46654363EFD_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_CACD548DCDD353CDA6FD326364EAA9F8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_81DB399824D4503785BC585DFD99791F" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_CACD548DCDD353CDA6FD326364EAA9F8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_98DC844781705273B099DFB14DE85FD6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_9034D97225B15330901FC3F7D8BE4145" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_98DC844781705273B099DFB14DE85FD6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_3FE3B520654894BC5B36A46654362D09_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_98DC844781705273B099DFB14DE85FD6" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_3FE3B520654894BC5B36A46654362D09_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_BA7BA7F3E9BE568F85D2CDEF0A19ACE9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_98DC844781705273B099DFB14DE85FD6" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_BA7BA7F3E9BE568F85D2CDEF0A19ACE9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLocationAxis" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLocationAxis_BEE6288C58AD5080B60E76CCB4E0C435" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_9034D97225B15330901FC3F7D8BE4145" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLocationAxis_BEE6288C58AD5080B60E76CCB4E0C435" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLocationDomain" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLocationDomain_517D6431A6647BAE7D7AA4665437424C_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLocationAxis_BEE6288C58AD5080B60E76CCB4E0C435" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLocationDomain_517D6431A6647BAE7D7AA4665437424C_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherComprehensiveIncomeLocationDomain" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLocationDomain_C0D277A255B35C759FD623306C34BD65" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLocationAxis_BEE6288C58AD5080B60E76CCB4E0C435" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLocationDomain_C0D277A255B35C759FD623306C34BD65" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_E7FDA820ECA85C9C9EE2FF0BBAF09842" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_9034D97225B15330901FC3F7D8BE4145" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_E7FDA820ECA85C9C9EE2FF0BBAF09842" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_3A44AA68D77540D8FBD8A4665437527E_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_E7FDA820ECA85C9C9EE2FF0BBAF09842" xlink:to="loc_us-gaap_HedgingRelationshipDomain_3A44AA68D77540D8FBD8A4665437527E_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:label="loc_us-gaap_HedgingRelationshipDomain_BBB22451EAEE5C5BA8B8AFC5771AA57B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_E7FDA820ECA85C9C9EE2FF0BBAF09842" xlink:to="loc_us-gaap_HedgingRelationshipDomain_BBB22451EAEE5C5BA8B8AFC5771AA57B" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/DocumentAndEntityInformationDocument" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityInformationLineItems" xlink:label="loc_dei_EntityInformationLineItems_561EA5172F6D56D99075CE595934277B" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntitiesTable" xlink:label="loc_dei_EntitiesTable_2F20DD37882054BA8EEEC434B3B57130" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_EntityInformationLineItems_561EA5172F6D56D99075CE595934277B" xlink:to="loc_dei_EntitiesTable_2F20DD37882054BA8EEEC434B3B57130" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_LegalEntityAxis" xlink:label="loc_dei_LegalEntityAxis_35360186C8A05C7181EA12D5CF6A18CC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_EntitiesTable_2F20DD37882054BA8EEEC434B3B57130" xlink:to="loc_dei_LegalEntityAxis_35360186C8A05C7181EA12D5CF6A18CC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_D42B606C11696F9E233DA466547CFC88_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_35360186C8A05C7181EA12D5CF6A18CC" xlink:to="loc_dei_EntityDomain_D42B606C11696F9E233DA466547CFC88_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityDomain" xlink:label="loc_dei_EntityDomain_F132E3B71EAD5C9197539A4B6C8BEC18" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_35360186C8A05C7181EA12D5CF6A18CC" xlink:to="loc_dei_EntityDomain_F132E3B71EAD5C9197539A4B6C8BEC18" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityRegistrantName" xlink:label="loc_dei_EntityRegistrantName_8084572B105E5AA5A570A3A6B03D0E93" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_561EA5172F6D56D99075CE595934277B" xlink:to="loc_dei_EntityRegistrantName_8084572B105E5AA5A570A3A6B03D0E93" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCentralIndexKey" xlink:label="loc_dei_EntityCentralIndexKey_0F420CBAAA9F5AA3A3FE261AFEFF495B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_561EA5172F6D56D99075CE595934277B" xlink:to="loc_dei_EntityCentralIndexKey_0F420CBAAA9F5AA3A3FE261AFEFF495B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:label="loc_dei_CurrentFiscalYearEndDate_D75FEAD87F8D5EAE86530E544A7E4B4F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_561EA5172F6D56D99075CE595934277B" xlink:to="loc_dei_CurrentFiscalYearEndDate_D75FEAD87F8D5EAE86530E544A7E4B4F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityFilerCategory" xlink:label="loc_dei_EntityFilerCategory_7E93FC3CCE75578493B2BB7968E4FFF5" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_561EA5172F6D56D99075CE595934277B" xlink:to="loc_dei_EntityFilerCategory_7E93FC3CCE75578493B2BB7968E4FFF5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentType" xlink:label="loc_dei_DocumentType_B5234C934786512A874DA086F185AF81" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_561EA5172F6D56D99075CE595934277B" xlink:to="loc_dei_DocumentType_B5234C934786512A874DA086F185AF81" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentPeriodEndDate" xlink:label="loc_dei_DocumentPeriodEndDate_A027721C6BD7575AA1B62A0651BB893D" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_561EA5172F6D56D99075CE595934277B" xlink:to="loc_dei_DocumentPeriodEndDate_A027721C6BD7575AA1B62A0651BB893D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:label="loc_dei_DocumentFiscalYearFocus_F245A92B98BA5E1591B6A261A0F901AF" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_561EA5172F6D56D99075CE595934277B" xlink:to="loc_dei_DocumentFiscalYearFocus_F245A92B98BA5E1591B6A261A0F901AF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:label="loc_dei_DocumentFiscalPeriodFocus_70A91D3BC7895A75BE8884179A8CC1D9" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_561EA5172F6D56D99075CE595934277B" xlink:to="loc_dei_DocumentFiscalPeriodFocus_70A91D3BC7895A75BE8884179A8CC1D9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_AmendmentFlag" xlink:label="loc_dei_AmendmentFlag_19938E0921A65C0C83255824578C4D43" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_561EA5172F6D56D99075CE595934277B" xlink:to="loc_dei_AmendmentFlag_19938E0921A65C0C83255824578C4D43" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/dei/2014/dei-2014-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:label="loc_dei_EntityCommonStockSharesOutstanding_E37CE8C509D75DE1AC26D054D97E3C11" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityInformationLineItems_561EA5172F6D56D99075CE595934277B" xlink:to="loc_dei_EntityCommonStockSharesOutstanding_E37CE8C509D75DE1AC26D054D97E3C11" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EarningsPerShare" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EarningsPerShareEarningsPerShareDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EarningsPerShareDilutedLineItems" xlink:label="loc_us-gaap_EarningsPerShareDilutedLineItems_D9999423821F5DF1AAB8588F8339440F" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable" xlink:label="loc_us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable_90130B20BAEF5187946D43B7546E7B2D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EarningsPerShareDilutedLineItems_D9999423821F5DF1AAB8588F8339440F" xlink:to="loc_us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable_90130B20BAEF5187946D43B7546E7B2D" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_C3A6D28047A65338A141B60A1CC3D529" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable_90130B20BAEF5187946D43B7546E7B2D" xlink:to="loc_us-gaap_AwardTypeAxis_C3A6D28047A65338A141B60A1CC3D529" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_07DD2BCC6CCA399EFF97A4665591F53C_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_C3A6D28047A65338A141B60A1CC3D529" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_07DD2BCC6CCA399EFF97A4665591F53C_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_B449BDD9E84E54D7992B651810189C6C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_C3A6D28047A65338A141B60A1CC3D529" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_B449BDD9E84E54D7992B651810189C6C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember_EAFA939D0CD854B5A0BC68E6CE05EDB5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_B449BDD9E84E54D7992B651810189C6C" xlink:to="loc_us-gaap_RestrictedStockMember_EAFA939D0CD854B5A0BC68E6CE05EDB5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_9F6E05D293C752F6A573150A4CC5F8C6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_B449BDD9E84E54D7992B651810189C6C" xlink:to="loc_us-gaap_EmployeeStockOptionMember_9F6E05D293C752F6A573150A4CC5F8C6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_52A5B390EE3B5DD398CEF881B1D7A4E6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedLineItems_D9999423821F5DF1AAB8588F8339440F" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_52A5B390EE3B5DD398CEF881B1D7A4E6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements" xlink:label="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_80A8697E821351948D208CDCC2B10EEF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedLineItems_D9999423821F5DF1AAB8588F8339440F" xlink:to="loc_us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements_80A8697E821351948D208CDCC2B10EEF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_10C48EAA7352547CA37FCF209C504183" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedLineItems_D9999423821F5DF1AAB8588F8339440F" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_10C48EAA7352547CA37FCF209C504183" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EarningsPerShareEarningsPerShareTables" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EarningsPerShareDilutedLineItems" xlink:label="loc_us-gaap_EarningsPerShareDilutedLineItems_CBC8228928A55B6D89D2751702F37B17" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable" xlink:label="loc_us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable_6E430034DD365A60A0191F2520DCBADC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EarningsPerShareDilutedLineItems_CBC8228928A55B6D89D2751702F37B17" xlink:to="loc_us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable_6E430034DD365A60A0191F2520DCBADC" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_09FC0C45975C5D318B77A62CBEB99B1F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEarningsPerShareDilutedByCommonClassTable_6E430034DD365A60A0191F2520DCBADC" xlink:to="loc_us-gaap_StatementClassOfStockAxis_09FC0C45975C5D318B77A62CBEB99B1F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_3785A5DD5154829C762CA46655804B14_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_09FC0C45975C5D318B77A62CBEB99B1F" xlink:to="loc_us-gaap_ClassOfStockDomain_3785A5DD5154829C762CA46655804B14_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_28B9363CBB765A6CA9BE0BE5C52E6691" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_09FC0C45975C5D318B77A62CBEB99B1F" xlink:to="loc_us-gaap_ClassOfStockDomain_28B9363CBB765A6CA9BE0BE5C52E6691" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock" xlink:label="loc_us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock_A2B779D62AE35B049C46275C2D864B2D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedLineItems_CBC8228928A55B6D89D2751702F37B17" xlink:to="loc_us-gaap_ScheduleOfWeightedAverageNumberOfSharesTableTextBlock_A2B779D62AE35B049C46275C2D864B2D" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EquityAwards" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EquityAwardsRestrictedSharesActivityTableDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AEBB8534E5855CC08E4675DECA4504CE" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_EEE443B06F495259B4E97B469E5DE5F6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AEBB8534E5855CC08E4675DECA4504CE" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_EEE443B06F495259B4E97B469E5DE5F6" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_A64E03F89264500C9BB460AD3610A777" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_EEE443B06F495259B4E97B469E5DE5F6" xlink:to="loc_us-gaap_AwardTypeAxis_A64E03F89264500C9BB460AD3610A777" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7D7E7F0282F3C010938487AABD5299E2_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_A64E03F89264500C9BB460AD3610A777" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7D7E7F0282F3C010938487AABD5299E2_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AB978245078150C3966C60DD8C4A18C4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_A64E03F89264500C9BB460AD3610A777" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AB978245078150C3966C60DD8C4A18C4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember_FF34F057FE185FB59D6B85C6E5575102" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_AB978245078150C3966C60DD8C4A18C4" xlink:to="loc_us-gaap_RestrictedStockMember_FF34F057FE185FB59D6B85C6E5575102" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9C0EF14236DA566C942995615B11BE0B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AEBB8534E5855CC08E4675DECA4504CE" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9C0EF14236DA566C942995615B11BE0B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_19B14B17AF675D3EA4B587866AD3D73C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9C0EF14236DA566C942995615B11BE0B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_19B14B17AF675D3EA4B587866AD3D73C" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_SharebasedCompensationArrangementbySharebasedPaymentAwardOtherThanOptionsSpinoffAdjustment" xlink:label="loc_trs_SharebasedCompensationArrangementbySharebasedPaymentAwardOtherThanOptionsSpinoffAdjustment_6B8CA77ACA605381BA18807CCE058BC5" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9C0EF14236DA566C942995615B11BE0B" xlink:to="loc_trs_SharebasedCompensationArrangementbySharebasedPaymentAwardOtherThanOptionsSpinoffAdjustment_6B8CA77ACA605381BA18807CCE058BC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_33258F57C304533E956B65FA79B896CA" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9C0EF14236DA566C942995615B11BE0B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_33258F57C304533E956B65FA79B896CA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_CCE40E27A94C5915BC347A0BE34036D2" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9C0EF14236DA566C942995615B11BE0B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_CCE40E27A94C5915BC347A0BE34036D2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_FBA448464042579A8B604F252E46B553" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_9C0EF14236DA566C942995615B11BE0B" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_FBA448464042579A8B604F252E46B553" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_DD8373FFB5E65564B54F692E8DFC5EF9" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AEBB8534E5855CC08E4675DECA4504CE" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_DD8373FFB5E65564B54F692E8DFC5EF9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_5DF93AD3718F56058CD1314D1B215918" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_DD8373FFB5E65564B54F692E8DFC5EF9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_5DF93AD3718F56058CD1314D1B215918" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_1B98B1ECC4B65F3BA8A40CF6CB2A7C38" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_DD8373FFB5E65564B54F692E8DFC5EF9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_1B98B1ECC4B65F3BA8A40CF6CB2A7C38" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_C35587C5921B54D8A20399B1E2BD91EA" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_DD8373FFB5E65564B54F692E8DFC5EF9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_C35587C5921B54D8A20399B1E2BD91EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_0F52E4CCB4665F6CAA0C1E04F772BE55" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_DD8373FFB5E65564B54F692E8DFC5EF9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_0F52E4CCB4665F6CAA0C1E04F772BE55" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_B0C59A367C0F556DBC6BE6FD3D32DD5D" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_AEBB8534E5855CC08E4675DECA4504CE" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_B0C59A367C0F556DBC6BE6FD3D32DD5D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_9EB2CC0EF0B35528BACB86686983C690" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_B0C59A367C0F556DBC6BE6FD3D32DD5D" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms_9EB2CC0EF0B35528BACB86686983C690" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedIntrinsicValue" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedIntrinsicValue_547439EF602F5762B4C0D3880F224CA8" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsAdditionalDisclosuresAbstract_B0C59A367C0F556DBC6BE6FD3D32DD5D" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedIntrinsicValue_547439EF602F5762B4C0D3880F224CA8" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EquityAwardsRestrictedSharesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_78E1EB69A588837A3E8F7582CC0D8267" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_78E1EB69A588837A3E8F7582CC0D8267" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis" xlink:label="loc_us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis_D855DDE458DACBBB24CE7582CC0DF00D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_78E1EB69A588837A3E8F7582CC0D8267" xlink:to="loc_us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis_D855DDE458DACBBB24CE7582CC0DF00D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityBasedArrangementsIndividualContractsTypeOfDeferredCompensationDomain" xlink:label="loc_us-gaap_EquityBasedArrangementsIndividualContractsTypeOfDeferredCompensationDomain_9E4CA69DA72C2312DF327582CC0DC6E0_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis_D855DDE458DACBBB24CE7582CC0DF00D" xlink:to="loc_us-gaap_EquityBasedArrangementsIndividualContractsTypeOfDeferredCompensationDomain_9E4CA69DA72C2312DF327582CC0DC6E0_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EquityBasedArrangementsIndividualContractsTypeOfDeferredCompensationDomain" xlink:label="loc_us-gaap_EquityBasedArrangementsIndividualContractsTypeOfDeferredCompensationDomain_9E4CA69DA72C2312DF327582CC0DC6E0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DeferredCompensationArrangementWithIndividualShareBasedPaymentsByTypeOfDeferredCompensationAxis_D855DDE458DACBBB24CE7582CC0DF00D" xlink:to="loc_us-gaap_EquityBasedArrangementsIndividualContractsTypeOfDeferredCompensationDomain_9E4CA69DA72C2312DF327582CC0DC6E0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredCompensationShareBasedPaymentsMember" xlink:label="loc_us-gaap_DeferredCompensationShareBasedPaymentsMember_3AF57542CD9308F43AFF7582CC0D40F2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityBasedArrangementsIndividualContractsTypeOfDeferredCompensationDomain_9E4CA69DA72C2312DF327582CC0DC6E0" xlink:to="loc_us-gaap_DeferredCompensationShareBasedPaymentsMember_3AF57542CD9308F43AFF7582CC0D40F2" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_MetricTypeAxis" xlink:label="loc_trs_MetricTypeAxis_FB28018455544EA215A17582CC0D943B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_78E1EB69A588837A3E8F7582CC0D8267" xlink:to="loc_trs_MetricTypeAxis_FB28018455544EA215A17582CC0D943B" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_MetricTypeDomain" xlink:label="loc_trs_MetricTypeDomain_EA3FC49A2B577842A48C7582CC0D2D5F_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_MetricTypeAxis_FB28018455544EA215A17582CC0D943B" xlink:to="loc_trs_MetricTypeDomain_EA3FC49A2B577842A48C7582CC0D2D5F_default" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_MetricTypeDomain" xlink:label="loc_trs_MetricTypeDomain_EA3FC49A2B577842A48C7582CC0D2D5F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_MetricTypeAxis_FB28018455544EA215A17582CC0D943B" xlink:to="loc_trs_MetricTypeDomain_EA3FC49A2B577842A48C7582CC0D2D5F" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_A3YearEpsCagrMetricMember" xlink:label="loc_trs_A3YearEpsCagrMetricMember_0C81FF816BE55C91E1B47582CC0D5456" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_MetricTypeDomain_EA3FC49A2B577842A48C7582CC0D2D5F" xlink:to="loc_trs_A3YearEpsCagrMetricMember_0C81FF816BE55C91E1B47582CC0D5456" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_TotalshareholderreturnmetricMember" xlink:label="loc_trs_TotalshareholderreturnmetricMember_CCDF1730208C394BE4247582CC0DADA2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_MetricTypeDomain_EA3FC49A2B577842A48C7582CC0D2D5F" xlink:to="loc_trs_TotalshareholderreturnmetricMember_CCDF1730208C394BE4247582CC0DADA2" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_EPSCAGRandcashgenerationmetricMemberMember" xlink:label="loc_trs_EPSCAGRandcashgenerationmetricMemberMember_811E16F0B8B2A4A73DA97582CC0DC76C" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_MetricTypeDomain_EA3FC49A2B577842A48C7582CC0D2D5F" xlink:to="loc_trs_EPSCAGRandcashgenerationmetricMemberMember_811E16F0B8B2A4A73DA97582CC0DC76C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_BAAD0D45C587E59510D77582CC0DCA04" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_78E1EB69A588837A3E8F7582CC0D8267" xlink:to="loc_us-gaap_RangeAxis_BAAD0D45C587E59510D77582CC0DCA04" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_7BC43C289814B719C1DC7582CC0D4D25_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_BAAD0D45C587E59510D77582CC0DCA04" xlink:to="loc_us-gaap_RangeMember_7BC43C289814B719C1DC7582CC0D4D25_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_7BC43C289814B719C1DC7582CC0D4D25" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_BAAD0D45C587E59510D77582CC0DCA04" xlink:to="loc_us-gaap_RangeMember_7BC43C289814B719C1DC7582CC0D4D25" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_D50810309C92FBF8F0DE7582CC0D8897" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_7BC43C289814B719C1DC7582CC0D4D25" xlink:to="loc_us-gaap_MinimumMember_D50810309C92FBF8F0DE7582CC0D8897" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_8F08817169D7945EE5397582CC0DDB35" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_7BC43C289814B719C1DC7582CC0D4D25" xlink:to="loc_us-gaap_MaximumMember_8F08817169D7945EE5397582CC0DDB35" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameAxis" xlink:label="loc_us-gaap_PlanNameAxis_B0E9DC752250B07B0CE57582CC0DC041" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_78E1EB69A588837A3E8F7582CC0D8267" xlink:to="loc_us-gaap_PlanNameAxis_B0E9DC752250B07B0CE57582CC0DC041" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_CB6C0EFBEC79918FC4DB7582CC0DBAE1_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_B0E9DC752250B07B0CE57582CC0DC041" xlink:to="loc_us-gaap_PlanNameDomain_CB6C0EFBEC79918FC4DB7582CC0DBAE1_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PlanNameDomain" xlink:label="loc_us-gaap_PlanNameDomain_CB6C0EFBEC79918FC4DB7582CC0DBAE1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_B0E9DC752250B07B0CE57582CC0DC041" xlink:to="loc_us-gaap_PlanNameDomain_CB6C0EFBEC79918FC4DB7582CC0DBAE1" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_Plan1Member" xlink:label="loc_trs_Plan1Member_F18456D46C18F66FB0EE7582CC0D434B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_CB6C0EFBEC79918FC4DB7582CC0DBAE1" xlink:to="loc_trs_Plan1Member_F18456D46C18F66FB0EE7582CC0D434B" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_Plan2Member" xlink:label="loc_trs_Plan2Member_5296C8FFA31D46590CB77582CC0D1F06" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_CB6C0EFBEC79918FC4DB7582CC0DBAE1" xlink:to="loc_trs_Plan2Member_5296C8FFA31D46590CB77582CC0D1F06" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_Plan3Member" xlink:label="loc_trs_Plan3Member_EE6077C5ABC3574A1C747582CC0D6670" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_CB6C0EFBEC79918FC4DB7582CC0DBAE1" xlink:to="loc_trs_Plan3Member_EE6077C5ABC3574A1C747582CC0D6670" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_Plan4Member" xlink:label="loc_trs_Plan4Member_53C2F9C788C68C3AAC8A7582CC0D867B" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_CB6C0EFBEC79918FC4DB7582CC0DBAE1" xlink:to="loc_trs_Plan4Member_53C2F9C788C68C3AAC8A7582CC0D867B" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_Plan5Member" xlink:label="loc_trs_Plan5Member_6F18BFEC982C4BCEDAF17582CC0D1339" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_CB6C0EFBEC79918FC4DB7582CC0DBAE1" xlink:to="loc_trs_Plan5Member_6F18BFEC982C4BCEDAF17582CC0D1339" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_Plan7Member" xlink:label="loc_trs_Plan7Member_75D4AE5CC95FC0CBDBDA7582CC0DF06F" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_CB6C0EFBEC79918FC4DB7582CC0DBAE1" xlink:to="loc_trs_Plan7Member_75D4AE5CC95FC0CBDBDA7582CC0DF06F" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_Plan8Member" xlink:label="loc_trs_Plan8Member_22400A1D31E009D93DE27582CC0D58B5" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_CB6C0EFBEC79918FC4DB7582CC0DBAE1" xlink:to="loc_trs_Plan8Member_22400A1D31E009D93DE27582CC0D58B5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_4CFD4811EBCE28D300C07582CC0DD7D7" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_78E1EB69A588837A3E8F7582CC0D8267" xlink:to="loc_us-gaap_AwardTypeAxis_4CFD4811EBCE28D300C07582CC0DD7D7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_FA913A7815903AA76CAD7582CC0D46B1_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_4CFD4811EBCE28D300C07582CC0DD7D7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_FA913A7815903AA76CAD7582CC0D46B1_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_FA913A7815903AA76CAD7582CC0D46B1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_4CFD4811EBCE28D300C07582CC0DD7D7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_FA913A7815903AA76CAD7582CC0D46B1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestrictedStockMember" xlink:label="loc_us-gaap_RestrictedStockMember_854E5F2721734512A3B67582CC0DFBE9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_FA913A7815903AA76CAD7582CC0D46B1" xlink:to="loc_us-gaap_RestrictedStockMember_854E5F2721734512A3B67582CC0DFBE9" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_ServiceBasedRestricedSharesMember" xlink:label="loc_trs_ServiceBasedRestricedSharesMember_CFDBF39D2A95522F549B7582CC0D3A7D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedStockMember_854E5F2721734512A3B67582CC0DFBE9" xlink:to="loc_trs_ServiceBasedRestricedSharesMember_CFDBF39D2A95522F549B7582CC0D3A7D" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_PerformanceBasedRestricedSharesMember" xlink:label="loc_trs_PerformanceBasedRestricedSharesMember_AC41FF502D86EEAD8AFC7582CC0DCDCF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestrictedStockMember_854E5F2721734512A3B67582CC0DFBE9" xlink:to="loc_trs_PerformanceBasedRestricedSharesMember_AC41FF502D86EEAD8AFC7582CC0DCDCF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualAxis" xlink:label="loc_us-gaap_TitleOfIndividualAxis_47884A39DAB9ED3F2DA27582CC0DB68B" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_78E1EB69A588837A3E8F7582CC0D8267" xlink:to="loc_us-gaap_TitleOfIndividualAxis_47884A39DAB9ED3F2DA27582CC0DB68B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_68139ACAD2A5B76795E67582CC0DDBE9_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TitleOfIndividualAxis_47884A39DAB9ED3F2DA27582CC0DB68B" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_68139ACAD2A5B76795E67582CC0DDBE9_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TitleOfIndividualWithRelationshipToEntityDomain" xlink:label="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_68139ACAD2A5B76795E67582CC0DDBE9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TitleOfIndividualAxis_47884A39DAB9ED3F2DA27582CC0DB68B" xlink:to="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_68139ACAD2A5B76795E67582CC0DDBE9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DirectorMember" xlink:label="loc_us-gaap_DirectorMember_8AA4E9B1A9F1DB5CB2CE7582CC0D0C13" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TitleOfIndividualWithRelationshipToEntityDomain_68139ACAD2A5B76795E67582CC0DDBE9" xlink:to="loc_us-gaap_DirectorMember_8AA4E9B1A9F1DB5CB2CE7582CC0D0C13" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredCompensationArrangementWithIndividualSharesIssued" xlink:label="loc_us-gaap_DeferredCompensationArrangementWithIndividualSharesIssued_1FC94E9445557D94972B7582CC0D67CC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_us-gaap_DeferredCompensationArrangementWithIndividualSharesIssued_1FC94E9445557D94972B7582CC0D67CC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_6DF45FCB476C1B0DBF677582CC0DDEAF" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_6DF45FCB476C1B0DBF677582CC0DDEAF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_0C3705904BD5F5CE21107582CC0DF202" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_0C3705904BD5F5CE21107582CC0DF202" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardIncentiveCompensationPlanThresholdTargetAwardForGrantingStockAward" xlink:label="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardIncentiveCompensationPlanThresholdTargetAwardForGrantingStockAward_F672A6D1EBBBB4BEB0297582CC0DCAC5" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardIncentiveCompensationPlanThresholdTargetAwardForGrantingStockAward_F672A6D1EBBBB4BEB0297582CC0DCAC5" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardCashValueOfIncentivePlan" xlink:label="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardCashValueOfIncentivePlan_3BF968BB50B179F0BCFC7582CC0D4682" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardCashValueOfIncentivePlan_3BF968BB50B179F0BCFC7582CC0D4682" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestricedSharesValueOfIncentivePlan" xlink:label="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestricedSharesValueOfIncentivePlan_5AA4D1C5C3B6C780881F7582CC0D4DC2" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestricedSharesValueOfIncentivePlan_5AA4D1C5C3B6C780881F7582CC0D4DC2" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentageEarnedBasedOnMetricOverPerformancePeriod" xlink:label="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentageEarnedBasedOnMetricOverPerformancePeriod_1C050667D9C45FED74C87582CC0D6A6C" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentageEarnedBasedOnMetricOverPerformancePeriod_1C050667D9C45FED74C87582CC0D6A6C" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_SharebasedCompensationArrangementbySharebasedPaymentAwardPerformancePeriodComplete" xlink:label="loc_trs_SharebasedCompensationArrangementbySharebasedPaymentAwardPerformancePeriodComplete_B2FFDF9C64774E01D6D17582CC0D45B1" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_trs_SharebasedCompensationArrangementbySharebasedPaymentAwardPerformancePeriodComplete_B2FFDF9C64774E01D6D17582CC0D45B1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_385402FD5C2C8E721B7D7582CC0DC3EF" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_385402FD5C2C8E721B7D7582CC0DC3EF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_EE1C9990D773455E0DB87582CC0D2807" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_EE1C9990D773455E0DB87582CC0D2807" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAmountOfSharesEarnedOfTargetAward" xlink:label="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAmountOfSharesEarnedOfTargetAward_6E784E373599D6CDE2647582CC0D74C9" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAmountOfSharesEarnedOfTargetAward_6E784E373599D6CDE2647582CC0D74C9" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentageAttained" xlink:label="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentageAttained_121570AC7EB16BE990C27582CC0D510E" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardPercentageAttained_121570AC7EB16BE990C27582CC0D510E" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPerformanceMetricsInRestrictedSharesAwardTypePlan" xlink:label="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPerformanceMetricsInRestrictedSharesAwardTypePlan_4F923856B4FA2CC31F537582CC0D8BDB" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_trs_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfPerformanceMetricsInRestrictedSharesAwardTypePlan_4F923856B4FA2CC31F537582CC0D8BDB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_E467EDCFA5EFD7131DFC7582CC0DEB71" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_E467EDCFA5EFD7131DFC7582CC0DEB71" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_9EF897A0301E0F3A143D7582CC0DFDF4" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_9EF897A0301E0F3A143D7582CC0DFDF4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_D6677AFB19253FCEADAE7582CC0DA3D5" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_1D83A734C594787C791B7582CC0DA860" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_D6677AFB19253FCEADAE7582CC0DA3D5" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EquityAwardsStockOptionActivityTableDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EquityAwardsStockOptionsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_438DE6C8E189BACE418275109EDE099D" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_C60C9C207B87FED515CF75109EDEB9EB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_438DE6C8E189BACE418275109EDE099D" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_C60C9C207B87FED515CF75109EDEB9EB" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AwardTypeAxis" xlink:label="loc_us-gaap_AwardTypeAxis_64D5DB9DA1B9CD77CCFC75109EDE4319" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_C60C9C207B87FED515CF75109EDEB9EB" xlink:to="loc_us-gaap_AwardTypeAxis_64D5DB9DA1B9CD77CCFC75109EDE4319" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1CDAC37F98B5BB9AEDB275109EDEB81A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_64D5DB9DA1B9CD77CCFC75109EDE4319" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1CDAC37F98B5BB9AEDB275109EDEB81A_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1CDAC37F98B5BB9AEDB275109EDEB81A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_64D5DB9DA1B9CD77CCFC75109EDE4319" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1CDAC37F98B5BB9AEDB275109EDEB81A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:label="loc_us-gaap_EmployeeStockOptionMember_87D033B990939D47465275109EDE4A14" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_1CDAC37F98B5BB9AEDB275109EDEB81A" xlink:to="loc_us-gaap_EmployeeStockOptionMember_87D033B990939D47465275109EDE4A14" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_107634B12C2DCEE4B1BF75109EDE5EF3" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_438DE6C8E189BACE418275109EDE099D" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions_107634B12C2DCEE4B1BF75109EDE5EF3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_952BA04E0B5A696C5CAB75109EDEF8F4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_438DE6C8E189BACE418275109EDE099D" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_952BA04E0B5A696C5CAB75109EDEF8F4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber_ED9DD35DAA1677F527D775109EDE901E" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_438DE6C8E189BACE418275109EDE099D" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestExercisableNumber_ED9DD35DAA1677F527D775109EDE901E" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_StockOptionsVested" xlink:label="loc_trs_StockOptionsVested_33E4843D327553FC743575109EDEED52" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_438DE6C8E189BACE418275109EDE099D" xlink:to="loc_trs_StockOptionsVested_33E4843D327553FC743575109EDEED52" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_1FF7AB0388E42E4608CE75109EDED343" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_438DE6C8E189BACE418275109EDE099D" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_1FF7AB0388E42E4608CE75109EDED343" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_4AF8E151A1027A6BACFA75109EDE4D05" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_438DE6C8E189BACE418275109EDE099D" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_4AF8E151A1027A6BACFA75109EDE4D05" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_9CC7020A7DBA158DFBD375109EDEEA3D" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_438DE6C8E189BACE418275109EDE099D" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate_9CC7020A7DBA158DFBD375109EDEEA3D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_C0DB24DEA92B9E6F464D75109EDE73A9" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_438DE6C8E189BACE418275109EDE099D" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate_C0DB24DEA92B9E6F464D75109EDE73A9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_EF81E62ACC09F6715FF975109EDE5FDC" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_438DE6C8E189BACE418275109EDE099D" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1_EF81E62ACC09F6715FF975109EDE5FDC" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EquityAwardsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EquityOfferingDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockLineItems" xlink:label="loc_us-gaap_ClassOfStockLineItems_AF3EC159612B508C98DE4A41EAF19B05" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_6986441B38075942A7E53D0ECE241FEC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_AF3EC159612B508C98DE4A41EAF19B05" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_6986441B38075942A7E53D0ECE241FEC" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_CE2EE89FA95650C5900C63461075880B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_6986441B38075942A7E53D0ECE241FEC" xlink:to="loc_us-gaap_StatementClassOfStockAxis_CE2EE89FA95650C5900C63461075880B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_BCF116E8BDF5DEB1BF0DA466542F315C_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_CE2EE89FA95650C5900C63461075880B" xlink:to="loc_us-gaap_ClassOfStockDomain_BCF116E8BDF5DEB1BF0DA466542F315C_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_7614DB58F3685E2EB536B75D46EEFAE4" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_CE2EE89FA95650C5900C63461075880B" xlink:to="loc_us-gaap_ClassOfStockDomain_7614DB58F3685E2EB536B75D46EEFAE4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CommonStockMember" xlink:label="loc_us-gaap_CommonStockMember_07162272953657F38B9B652CAB3C2883" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_7614DB58F3685E2EB536B75D46EEFAE4" xlink:to="loc_us-gaap_CommonStockMember_07162272953657F38B9B652CAB3C2883" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_01F3A2CC6ECF57EAB0E08085D6C7F488" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_AF3EC159612B508C98DE4A41EAF19B05" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesNewIssues_01F3A2CC6ECF57EAB0E08085D6C7F488" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SaleOfStockPricePerShare" xlink:label="loc_us-gaap_SaleOfStockPricePerShare_F143675132865C1B8B9CA708D4D48AD2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_AF3EC159612B508C98DE4A41EAF19B05" xlink:to="loc_us-gaap_SaleOfStockPricePerShare_F143675132865C1B8B9CA708D4D48AD2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PaymentsOfStockIssuanceCosts" xlink:label="loc_us-gaap_PaymentsOfStockIssuanceCosts_97CB1BE3E8AD545DA3BB432AFC3E03B8" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_AF3EC159612B508C98DE4A41EAF19B05" xlink:to="loc_us-gaap_PaymentsOfStockIssuanceCosts_97CB1BE3E8AD545DA3BB432AFC3E03B8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_72A4AC29774C507889919CEE4D297A5E" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_AF3EC159612B508C98DE4A41EAF19B05" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfCommonStock_72A4AC29774C507889919CEE4D297A5E" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EquityOfferingNotes" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockLineItems" xlink:label="loc_us-gaap_ClassOfStockLineItems_60374D606A1F5C0F90A2455FD9CF1F29" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_49E24E1EC21B54F9A0E2A40E95C581D1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_60374D606A1F5C0F90A2455FD9CF1F29" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_49E24E1EC21B54F9A0E2A40E95C581D1" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:label="loc_us-gaap_StatementClassOfStockAxis_2ACA3DDFBF2E53ED827CAA6D7308F12C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_49E24E1EC21B54F9A0E2A40E95C581D1" xlink:to="loc_us-gaap_StatementClassOfStockAxis_2ACA3DDFBF2E53ED827CAA6D7308F12C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_F5F06237BC3B2D8B61EFA466568DCEF6_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2ACA3DDFBF2E53ED827CAA6D7308F12C" xlink:to="loc_us-gaap_ClassOfStockDomain_F5F06237BC3B2D8B61EFA466568DCEF6_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:label="loc_us-gaap_ClassOfStockDomain_C72B6B41C543567D97268F9A272A84A9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_2ACA3DDFBF2E53ED827CAA6D7308F12C" xlink:to="loc_us-gaap_ClassOfStockDomain_C72B6B41C543567D97268F9A272A84A9" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/EquityOfferingTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/FacilityClosuresNarrativeDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestructuringCostAndReserveLineItems" xlink:label="loc_us-gaap_RestructuringCostAndReserveLineItems_CC019708E6F16C7DFA527A968846738E" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTable" xlink:label="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_D1CAAE178E3898248EA37A9688448C3B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_CC019708E6F16C7DFA527A968846738E" xlink:to="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_D1CAAE178E3898248EA37A9688448C3B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_1025B4AB9530E06334007A968844E76B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_D1CAAE178E3898248EA37A9688448C3B" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_1025B4AB9530E06334007A968844E76B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_71803846107E45CF6EF37A968844F311_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_1025B4AB9530E06334007A968844E76B" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_71803846107E45CF6EF37A968844F311_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_71803846107E45CF6EF37A968844F311" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_1025B4AB9530E06334007A968844E76B" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_71803846107E45CF6EF37A968844F311" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CostOfSalesMember" xlink:label="loc_us-gaap_CostOfSalesMember_FB451472DA01D4A775A97A968844A072" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_71803846107E45CF6EF37A968844F311" xlink:to="loc_us-gaap_CostOfSalesMember_FB451472DA01D4A775A97A968844A072" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_CEFE898853A9CD689D797A968844116A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_71803846107E45CF6EF37A968844F311" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_CEFE898853A9CD689D797A968844116A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestructuringCostAndReserveAxis" xlink:label="loc_us-gaap_RestructuringCostAndReserveAxis_6B35F94355E6439FD9657A968846E6DD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRestructuringAndRelatedCostsTable_D1CAAE178E3898248EA37A9688448C3B" xlink:to="loc_us-gaap_RestructuringCostAndReserveAxis_6B35F94355E6439FD9657A968846E6DD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_75424596A5F0554557727A968846302A_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_6B35F94355E6439FD9657A968846E6DD" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_75424596A5F0554557727A968846302A_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TypeOfRestructuringDomain" xlink:label="loc_us-gaap_TypeOfRestructuringDomain_75424596A5F0554557727A968846302A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RestructuringCostAndReserveAxis_6B35F94355E6439FD9657A968846E6DD" xlink:to="loc_us-gaap_TypeOfRestructuringDomain_75424596A5F0554557727A968846302A" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_FacilityClosingReynosaMexicoMember" xlink:label="loc_trs_FacilityClosingReynosaMexicoMember_E5DB299C968E56546A7F7A968846C3D1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_75424596A5F0554557727A968846302A" xlink:to="loc_trs_FacilityClosingReynosaMexicoMember_E5DB299C968E56546A7F7A968846C3D1" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_FacilityClosingWolverhamptonUnitedKingdomMember" xlink:label="loc_trs_FacilityClosingWolverhamptonUnitedKingdomMember_E212D7BEE9FD17B1B5AB7A968846C064" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfRestructuringDomain_75424596A5F0554557727A968846302A" xlink:to="loc_trs_FacilityClosingWolverhamptonUnitedKingdomMember_E212D7BEE9FD17B1B5AB7A968846C064" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_FutureLeaseObligationNetofSubleaseIncome" xlink:label="loc_trs_FutureLeaseObligationNetofSubleaseIncome_A072CC083D040BBA40BA7A96884673CB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_CC019708E6F16C7DFA527A968846738E" xlink:to="loc_trs_FutureLeaseObligationNetofSubleaseIncome_A072CC083D040BBA40BA7A96884673CB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestructuringAndRelatedCostExpectedNumberOfPositionsEliminated" xlink:label="loc_us-gaap_RestructuringAndRelatedCostExpectedNumberOfPositionsEliminated_D208DFA756C80418D55F7A9688461E41" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_CC019708E6F16C7DFA527A968846738E" xlink:to="loc_us-gaap_RestructuringAndRelatedCostExpectedNumberOfPositionsEliminated_D208DFA756C80418D55F7A9688461E41" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SeveranceCosts1" xlink:label="loc_us-gaap_SeveranceCosts1_DBAD323F71EF07C4480E7A9688468D04" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_CC019708E6F16C7DFA527A968846738E" xlink:to="loc_us-gaap_SeveranceCosts1_DBAD323F71EF07C4480E7A9688468D04" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RestructuringReserveAcceleratedDepreciation" xlink:label="loc_us-gaap_RestructuringReserveAcceleratedDepreciation_6EEF5C69217070AB98B77A9688468B07" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_CC019708E6F16C7DFA527A968846738E" xlink:to="loc_us-gaap_RestructuringReserveAcceleratedDepreciation_6EEF5C69217070AB98B77A9688468B07" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GainLossOnSaleOfBusiness" xlink:label="loc_us-gaap_GainLossOnSaleOfBusiness_455463F03EC7EFF1B8427A968847F373" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_CC019708E6F16C7DFA527A968846738E" xlink:to="loc_us-gaap_GainLossOnSaleOfBusiness_455463F03EC7EFF1B8427A968847F373" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GainLossOnDispositionOfAssets1" xlink:label="loc_us-gaap_GainLossOnDispositionOfAssets1_5A3F7E3664DB8A497DAC7A9688477AA0" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RestructuringCostAndReserveLineItems_CC019708E6F16C7DFA527A968846738E" xlink:to="loc_us-gaap_GainLossOnDispositionOfAssets1_5A3F7E3664DB8A497DAC7A9688477AA0" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/FacilityClosuresRestructuringAndRelatedActivitiesDisclosureNotes" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/GoodwillAndOtherIntangibleAssets" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/GoodwillAndOtherIntangibleAssetsGoodwillAndOtherIntangibleAssetsTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/GoodwillAndOtherIntangibleAssetsGoodwillRollforwardDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GoodwillLineItems" xlink:label="loc_us-gaap_GoodwillLineItems_1F94EAE7F1FD5DF595BA031CB20CABC0" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfGoodwillTable" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_2DAF1A444E8B5A8EBE25D25663B13126" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_1F94EAE7F1FD5DF595BA031CB20CABC0" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_2DAF1A444E8B5A8EBE25D25663B13126" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_842448E68C75507A9C9A479A4263F951" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_2DAF1A444E8B5A8EBE25D25663B13126" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_842448E68C75507A9C9A479A4263F951" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_3062A05C4E868547FD41A466567955E7_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_842448E68C75507A9C9A479A4263F951" xlink:to="loc_us-gaap_SegmentDomain_3062A05C4E868547FD41A466567955E7_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_784F008281CA5046927C37E4FF857566" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_842448E68C75507A9C9A479A4263F951" xlink:to="loc_us-gaap_SegmentDomain_784F008281CA5046927C37E4FF857566" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_PackagingReportableSegmentMember" xlink:label="loc_trs_PackagingReportableSegmentMember_BD371576842B599F95434C82ABA752F7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_784F008281CA5046927C37E4FF857566" xlink:to="loc_trs_PackagingReportableSegmentMember_BD371576842B599F95434C82ABA752F7" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_EnergyReportableSegmentMember" xlink:label="loc_trs_EnergyReportableSegmentMember_799D67F9C295590681EE0737C32575D6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_784F008281CA5046927C37E4FF857566" xlink:to="loc_trs_EnergyReportableSegmentMember_799D67F9C295590681EE0737C32575D6" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_AerospaceDefenseReportableSegmentMember" xlink:label="loc_trs_AerospaceDefenseReportableSegmentMember_68B6EE3858ED5709A50FFCBA7BAAB7B8" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_784F008281CA5046927C37E4FF857566" xlink:to="loc_trs_AerospaceDefenseReportableSegmentMember_68B6EE3858ED5709A50FFCBA7BAAB7B8" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_EngineeredComponentsReportableSegmentMember" xlink:label="loc_trs_EngineeredComponentsReportableSegmentMember_CDE6E0AA00215A4A9F78236AED6A9AA9" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_784F008281CA5046927C37E4FF857566" xlink:to="loc_trs_EngineeredComponentsReportableSegmentMember_CDE6E0AA00215A4A9F78236AED6A9AA9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GoodwillRollForward" xlink:label="loc_us-gaap_GoodwillRollForward_EA7DEAA7EA3C5641BF800BDFB33BCF63" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_1F94EAE7F1FD5DF595BA031CB20CABC0" xlink:to="loc_us-gaap_GoodwillRollForward_EA7DEAA7EA3C5641BF800BDFB33BCF63" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Goodwill" xlink:label="loc_us-gaap_Goodwill_35839168C3B65ECB955C162B5D2486B0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_EA7DEAA7EA3C5641BF800BDFB33BCF63" xlink:to="loc_us-gaap_Goodwill_35839168C3B65ECB955C162B5D2486B0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GoodwillAcquiredDuringPeriod" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_CF84A07A92F75B70A1CAA6F2EF6A8DB2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_EA7DEAA7EA3C5641BF800BDFB33BCF63" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_CF84A07A92F75B70A1CAA6F2EF6A8DB2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit" xlink:label="loc_us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit_C8EEA8989BC55C92BE6CCBA5DC38A139" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_EA7DEAA7EA3C5641BF800BDFB33BCF63" xlink:to="loc_us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit_C8EEA8989BC55C92BE6CCBA5DC38A139" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_GoodwillTranslationAndPurchaseAccountingAdjustments" xlink:label="loc_us-gaap_GoodwillTranslationAndPurchaseAccountingAdjustments_883D76A8D21F52AF9DD668190B2E8A63" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_EA7DEAA7EA3C5641BF800BDFB33BCF63" xlink:to="loc_us-gaap_GoodwillTranslationAndPurchaseAccountingAdjustments_883D76A8D21F52AF9DD668190B2E8A63" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/GoodwillAndOtherIntangibleAssetsScheduleOfFiniteLivedIntangibleAssetsAmortizationExpenseDetails" xlink:type="extended">
    <link:loc xlink:href="trs-20170630.xsd#trs_AmortizationOfIntangibleAssetsLineItems" xlink:label="loc_trs_AmortizationOfIntangibleAssetsLineItems_CC83D7CEAFFF58639C30DAB7B8D52DE7" xlink:type="locator" />
    <link:loc xlink:href="trs-20170630.xsd#trs_ScheduleOfAmortizationOfIntangibleAssetsTable" xlink:label="loc_trs_ScheduleOfAmortizationOfIntangibleAssetsTable_2672F028BB9E5404BB541CB429C5E54A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_trs_AmortizationOfIntangibleAssetsLineItems_CC83D7CEAFFF58639C30DAB7B8D52DE7" xlink:to="loc_trs_ScheduleOfAmortizationOfIntangibleAssetsTable_2672F028BB9E5404BB541CB429C5E54A" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_C51C5DB5B0FA5E42A1A8917C0E01AC34" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfAmortizationOfIntangibleAssetsTable_2672F028BB9E5404BB541CB429C5E54A" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_C51C5DB5B0FA5E42A1A8917C0E01AC34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_51AD7FC36E55EA5517E6A466553EAF05_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_C51C5DB5B0FA5E42A1A8917C0E01AC34" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_51AD7FC36E55EA5517E6A466553EAF05_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_E621D9A67ED8580BAB7B1050B530F540" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_C51C5DB5B0FA5E42A1A8917C0E01AC34" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_E621D9A67ED8580BAB7B1050B530F540" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CostOfSalesMember" xlink:label="loc_us-gaap_CostOfSalesMember_959D600AC6E059C2827708F2F916500E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_E621D9A67ED8580BAB7B1050B530F540" xlink:to="loc_us-gaap_CostOfSalesMember_959D600AC6E059C2827708F2F916500E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_275CE867EDDC5177B1CFD3F9B3E2948E" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_E621D9A67ED8580BAB7B1050B530F540" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_275CE867EDDC5177B1CFD3F9B3E2948E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_CC189F1E681B5CA8ACA5955D342CDA07" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfAmortizationOfIntangibleAssetsTable_2672F028BB9E5404BB541CB429C5E54A" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_CC189F1E681B5CA8ACA5955D342CDA07" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_11A972AE20B30C3A8DE2A466553E522C_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_CC189F1E681B5CA8ACA5955D342CDA07" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_11A972AE20B30C3A8DE2A466553E522C_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_C09AFC3C938F5E8E8902B5F8A77AA90B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_CC189F1E681B5CA8ACA5955D342CDA07" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_C09AFC3C938F5E8E8902B5F8A77AA90B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherIntangibleAssetsMember" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_E7E6F96DC7E859A5AE7F70C37F443448" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_C09AFC3C938F5E8E8902B5F8A77AA90B" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_E7E6F96DC7E859A5AE7F70C37F443448" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember_DE8AEB7FE0E050CAA1A34BB07A2FF390" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_C09AFC3C938F5E8E8902B5F8A77AA90B" xlink:to="loc_us-gaap_CustomerRelationshipsMember_DE8AEB7FE0E050CAA1A34BB07A2FF390" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_8FE557BDD39F594EA9D5EA6C74C5A4FF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_AmortizationOfIntangibleAssetsLineItems_CC83D7CEAFFF58639C30DAB7B8D52DE7" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_8FE557BDD39F594EA9D5EA6C74C5A4FF" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/GoodwillAndOtherIntangibleAssetsScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassDetails" xlink:type="extended">
    <link:loc xlink:href="trs-20170630.xsd#trs_IntangibleAssetsExcludingGoodwillLineItems" xlink:label="loc_trs_IntangibleAssetsExcludingGoodwillLineItems_685A8F829B3E527D99B37B2B02DF9A21" xlink:type="locator" />
    <link:loc xlink:href="trs-20170630.xsd#trs_ScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassTable" xlink:label="loc_trs_ScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassTable_FF11E1F3D20857E7A518B4A98896D117" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_trs_IntangibleAssetsExcludingGoodwillLineItems_685A8F829B3E527D99B37B2B02DF9A21" xlink:to="loc_trs_ScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassTable_FF11E1F3D20857E7A518B4A98896D117" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_F6A4E6AACDEC5CB9970445847906DA5B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassTable_FF11E1F3D20857E7A518B4A98896D117" xlink:to="loc_us-gaap_RangeAxis_F6A4E6AACDEC5CB9970445847906DA5B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_64EE317E6697797D4DA9A466550D892A_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_F6A4E6AACDEC5CB9970445847906DA5B" xlink:to="loc_us-gaap_RangeMember_64EE317E6697797D4DA9A466550D892A_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_DC1F5D330BC659D89F6EB06AF1326CC7" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_F6A4E6AACDEC5CB9970445847906DA5B" xlink:to="loc_us-gaap_RangeMember_DC1F5D330BC659D89F6EB06AF1326CC7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_DFEEC26B2ED25231858AB3633B8B4C6C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_DC1F5D330BC659D89F6EB06AF1326CC7" xlink:to="loc_us-gaap_MinimumMember_DFEEC26B2ED25231858AB3633B8B4C6C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_9AA347625B655851975075A44FCEC2D0" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_DC1F5D330BC659D89F6EB06AF1326CC7" xlink:to="loc_us-gaap_MaximumMember_9AA347625B655851975075A44FCEC2D0" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_FiniteLivedIntangibleAssetsByUsefulLifeAxis" xlink:label="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeAxis_98BC5D0E6E8C515A9FD0AA2373C566F4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassTable_FF11E1F3D20857E7A518B4A98896D117" xlink:to="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeAxis_98BC5D0E6E8C515A9FD0AA2373C566F4" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain" xlink:label="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_38B4969D4E38D4F86A87A466550F606A_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeAxis_98BC5D0E6E8C515A9FD0AA2373C566F4" xlink:to="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_38B4969D4E38D4F86A87A466550F606A_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain" xlink:label="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_804754232F765BD6A93AED3DC44DF680" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeAxis_98BC5D0E6E8C515A9FD0AA2373C566F4" xlink:to="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_804754232F765BD6A93AED3DC44DF680" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_UsefulLifeFiveToTwelveYearsMember" xlink:label="loc_trs_UsefulLifeFiveToTwelveYearsMember_DE830B18A2875FDC907026C4F743BEFD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_804754232F765BD6A93AED3DC44DF680" xlink:to="loc_trs_UsefulLifeFiveToTwelveYearsMember_DE830B18A2875FDC907026C4F743BEFD" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_UsefulLifeFifteenToTwentyfiveYearsMember" xlink:label="loc_trs_UsefulLifeFifteenToTwentyfiveYearsMember_4EA63DA6AB6A59DF82AD2CD0C47152E6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_804754232F765BD6A93AED3DC44DF680" xlink:to="loc_trs_UsefulLifeFifteenToTwentyfiveYearsMember_4EA63DA6AB6A59DF82AD2CD0C47152E6" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_UsefulLifeOneToFifteenYearsMember" xlink:label="loc_trs_UsefulLifeOneToFifteenYearsMember_07EB9268A03D5CC7BC019677C87D0E1F" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_804754232F765BD6A93AED3DC44DF680" xlink:to="loc_trs_UsefulLifeOneToFifteenYearsMember_07EB9268A03D5CC7BC019677C87D0E1F" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_UsefulLifeSeventeenToThirtyYearsMember" xlink:label="loc_trs_UsefulLifeSeventeenToThirtyYearsMember_C3CF305EC8205EDCAA5910F42087BB8F" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_FiniteLivedIntangibleAssetsByUsefulLifeDomain_804754232F765BD6A93AED3DC44DF680" xlink:to="loc_trs_UsefulLifeSeventeenToThirtyYearsMember_C3CF305EC8205EDCAA5910F42087BB8F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_937A75F8D5E853A498625220686749D3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassTable_FF11E1F3D20857E7A518B4A98896D117" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_937A75F8D5E853A498625220686749D3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_CA76C3626E091EACFBBBA4665510BE21_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_937A75F8D5E853A498625220686749D3" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_CA76C3626E091EACFBBBA4665510BE21_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5E621D74A6785B9B981C0AF7823A8D9B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_937A75F8D5E853A498625220686749D3" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5E621D74A6785B9B981C0AF7823A8D9B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CustomerRelationshipsMember" xlink:label="loc_us-gaap_CustomerRelationshipsMember_9E1E8EA5F7815230B56E174C28540947" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5E621D74A6785B9B981C0AF7823A8D9B" xlink:to="loc_us-gaap_CustomerRelationshipsMember_9E1E8EA5F7815230B56E174C28540947" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OtherIntangibleAssetsMember" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_73E7F03650F350BA8A6A0302306AB147" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5E621D74A6785B9B981C0AF7823A8D9B" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_73E7F03650F350BA8A6A0302306AB147" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_C871742DD11452F88A42688A5A839AA3" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfIntangibleAssetsExcludingGoodwillByMajorClassTable_FF11E1F3D20857E7A518B4A98896D117" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_C871742DD11452F88A42688A5A839AA3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_0E5F823E665E061E5167A4665510B2D1_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_C871742DD11452F88A42688A5A839AA3" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_0E5F823E665E061E5167A4665510B2D1_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_DFE8D05440845D1392318108F192B75D" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_C871742DD11452F88A42688A5A839AA3" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_DFE8D05440845D1392318108F192B75D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TrademarksAndTradeNamesMember" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_CC45FD5DC9455F64A5416C6912AB2704" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_DFE8D05440845D1392318108F192B75D" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_CC45FD5DC9455F64A5416C6912AB2704" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_1C51CEB0282B5619AFB3ED9F26630B0B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_IntangibleAssetsExcludingGoodwillLineItems_685A8F829B3E527D99B37B2B02DF9A21" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_1C51CEB0282B5619AFB3ED9F26630B0B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_600C0BD46EA25CB5922A62C616DBBBF1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_IntangibleAssetsExcludingGoodwillLineItems_685A8F829B3E527D99B37B2B02DF9A21" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_600C0BD46EA25CB5922A62C616DBBBF1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_A31C4DC612CC58589E9AA989764672DF" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_IntangibleAssetsExcludingGoodwillLineItems_685A8F829B3E527D99B37B2B02DF9A21" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_A31C4DC612CC58589E9AA989764672DF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IntangibleAssetsGrossExcludingGoodwill" xlink:label="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_A9172547C23C5F4A9401DEE1ADA8B052" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_IntangibleAssetsExcludingGoodwillLineItems_685A8F829B3E527D99B37B2B02DF9A21" xlink:to="loc_us-gaap_IntangibleAssetsGrossExcludingGoodwill_A9172547C23C5F4A9401DEE1ADA8B052" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_742FF3FCDEF056ACA48DF8FF3D8CB3C1" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_IntangibleAssetsExcludingGoodwillLineItems_685A8F829B3E527D99B37B2B02DF9A21" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_742FF3FCDEF056ACA48DF8FF3D8CB3C1" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/Inventories" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/InventoriesDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/InventoriesTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/LongTermDebt" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/LongTermDebtCreditAgreementDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_25594308CB725DF390277B72478ACC12" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_DebtInstrumentTable_25594308CB725DF390277B72478ACC12" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="trs-20170630.xsd#trs_PrincipalPaymentScheduleAxis" xlink:label="loc_trs_PrincipalPaymentScheduleAxis_D84CAB0F82895C5C9D51E1F5C7F72B44" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_25594308CB725DF390277B72478ACC12" xlink:to="loc_trs_PrincipalPaymentScheduleAxis_D84CAB0F82895C5C9D51E1F5C7F72B44" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_PrincipalPaymentScheduleDomain" xlink:label="loc_trs_PrincipalPaymentScheduleDomain_724451562B6BECED93D4A577642A7EE8_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_PrincipalPaymentScheduleAxis_D84CAB0F82895C5C9D51E1F5C7F72B44" xlink:to="loc_trs_PrincipalPaymentScheduleDomain_724451562B6BECED93D4A577642A7EE8_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_PrincipalPaymentScheduleDomain" xlink:label="loc_trs_PrincipalPaymentScheduleDomain_C16B9A1BDE96546AB1B2A2C1DE05063F" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_PrincipalPaymentScheduleAxis_D84CAB0F82895C5C9D51E1F5C7F72B44" xlink:to="loc_trs_PrincipalPaymentScheduleDomain_C16B9A1BDE96546AB1B2A2C1DE05063F" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_PrincipalpaymentquarterlyDecember2015throughSeptember2018Member" xlink:label="loc_trs_PrincipalpaymentquarterlyDecember2015throughSeptember2018Member_F6633C741BF65F83B3AA3A02F5ADC05C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_PrincipalPaymentScheduleDomain_C16B9A1BDE96546AB1B2A2C1DE05063F" xlink:to="loc_trs_PrincipalpaymentquarterlyDecember2015throughSeptember2018Member_F6633C741BF65F83B3AA3A02F5ADC05C" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_PrincipalpaymentquarterlyDecember2018throughMarch2020Member" xlink:label="loc_trs_PrincipalpaymentquarterlyDecember2018throughMarch2020Member_4CAF923CC68F578A97E18FBECAA834B4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_PrincipalPaymentScheduleDomain_C16B9A1BDE96546AB1B2A2C1DE05063F" xlink:to="loc_trs_PrincipalpaymentquarterlyDecember2018throughMarch2020Member_4CAF923CC68F578A97E18FBECAA834B4" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_FinalprincipalpaymentJune302020Member" xlink:label="loc_trs_FinalprincipalpaymentJune302020Member_E4B6AEBE9F085601854FF5FF8CFC4A43" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_PrincipalPaymentScheduleDomain_C16B9A1BDE96546AB1B2A2C1DE05063F" xlink:to="loc_trs_FinalprincipalpaymentJune302020Member_E4B6AEBE9F085601854FF5FF8CFC4A43" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_7D5AE20F5F265C77B39B144431A2F799" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_25594308CB725DF390277B72478ACC12" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_7D5AE20F5F265C77B39B144431A2F799" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_47AE5F330A99B62CD4DEA577642ACD15_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_7D5AE20F5F265C77B39B144431A2F799" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_47AE5F330A99B62CD4DEA577642ACD15_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6A5426D08BD15D0A997F4C2ED32ACC97" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_7D5AE20F5F265C77B39B144431A2F799" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6A5426D08BD15D0A997F4C2ED32ACC97" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_A10888C052175FE18B03609CFCC9D536" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6A5426D08BD15D0A997F4C2ED32ACC97" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_A10888C052175FE18B03609CFCC9D536" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_CD565D9B182452BDA1B3B0B97EA19B8A" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_25594308CB725DF390277B72478ACC12" xlink:to="loc_us-gaap_CreditFacilityAxis_CD565D9B182452BDA1B3B0B97EA19B8A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_752C7E38CA70F9149EBBA577642AE05E_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_CD565D9B182452BDA1B3B0B97EA19B8A" xlink:to="loc_us-gaap_CreditFacilityDomain_752C7E38CA70F9149EBBA577642AE05E_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_6387A2D2CF335ECFA3A2B1CA2B2B6EDB" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_CD565D9B182452BDA1B3B0B97EA19B8A" xlink:to="loc_us-gaap_CreditFacilityDomain_6387A2D2CF335ECFA3A2B1CA2B2B6EDB" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_TermloanAfacilityMember" xlink:label="loc_trs_TermloanAfacilityMember_0481AC42EC775989A9BD257EBD2F1B0C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_6387A2D2CF335ECFA3A2B1CA2B2B6EDB" xlink:to="loc_trs_TermloanAfacilityMember_0481AC42EC775989A9BD257EBD2F1B0C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_4432144147115A2898D2B89D14E3CE35" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_6387A2D2CF335ECFA3A2B1CA2B2B6EDB" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_4432144147115A2898D2B89D14E3CE35" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LetterOfCreditMember" xlink:label="loc_us-gaap_LetterOfCreditMember_7CA7901ECA685174803794811B321B83" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_6387A2D2CF335ECFA3A2B1CA2B2B6EDB" xlink:to="loc_us-gaap_LetterOfCreditMember_7CA7901ECA685174803794811B321B83" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_70733C0B240A5929B20CD80CDAD56B86" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_25594308CB725DF390277B72478ACC12" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_70733C0B240A5929B20CD80CDAD56B86" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_1DEB27EAC9B6792AB276A577642A9852_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_70733C0B240A5929B20CD80CDAD56B86" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_1DEB27EAC9B6792AB276A577642A9852_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_35BC03FC481752EDA64DFC923B729ACA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_70733C0B240A5929B20CD80CDAD56B86" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_35BC03FC481752EDA64DFC923B729ACA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_5488CB12AE1657699E971C4142958A24" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_35BC03FC481752EDA64DFC923B729ACA" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_5488CB12AE1657699E971C4142958A24" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_SeniorSecuredTermLoanMember" xlink:label="loc_trs_SeniorSecuredTermLoanMember_CBDB315DCF555ACFBD4521910FFFD2E6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_35BC03FC481752EDA64DFC923B729ACA" xlink:to="loc_trs_SeniorSecuredTermLoanMember_CBDB315DCF555ACFBD4521910FFFD2E6" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_TermloanAfacilityMember" xlink:label="loc_trs_TermloanAfacilityMember_4F83AD1EA6115791A96D23150EDF7922" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_35BC03FC481752EDA64DFC923B729ACA" xlink:to="loc_trs_TermloanAfacilityMember_4F83AD1EA6115791A96D23150EDF7922" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_62628A38F62A51DBAC3459BCFA446427" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_25594308CB725DF390277B72478ACC12" xlink:to="loc_us-gaap_DebtInstrumentAxis_62628A38F62A51DBAC3459BCFA446427" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_8D713A61FE1C1E001982A577642AA131_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_62628A38F62A51DBAC3459BCFA446427" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_8D713A61FE1C1E001982A577642AA131_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_4E6D8D927A295B30B234753853668BE9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_62628A38F62A51DBAC3459BCFA446427" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_4E6D8D927A295B30B234753853668BE9" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_BankdebtandreceivablesfacilityMember" xlink:label="loc_trs_BankdebtandreceivablesfacilityMember_4E6128885920583CA873D4DC1F055C3C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4E6D8D927A295B30B234753853668BE9" xlink:to="loc_trs_BankdebtandreceivablesfacilityMember_4E6128885920583CA873D4DC1F055C3C" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_RevolvingCreditAndTermLoanFacilitiesMember" xlink:label="loc_trs_RevolvingCreditAndTermLoanFacilitiesMember_9A9E55C9FC0E565186DDEBF6B225008F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4E6D8D927A295B30B234753853668BE9" xlink:to="loc_trs_RevolvingCreditAndTermLoanFacilitiesMember_9A9E55C9FC0E565186DDEBF6B225008F" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_TermloanAfacilityMember" xlink:label="loc_trs_TermloanAfacilityMember_0841EAF3B29F52DD86FE4270C0A769C3" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4E6D8D927A295B30B234753853668BE9" xlink:to="loc_trs_TermloanAfacilityMember_0841EAF3B29F52DD86FE4270C0A769C3" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_0B5C52F136785ADFB2D647480A4672EA" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_4E6D8D927A295B30B234753853668BE9" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_0B5C52F136785ADFB2D647480A4672EA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount" xlink:label="loc_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_74632A9E3BC852BEB7B4BCB48B9C31B6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_74632A9E3BC852BEB7B4BCB48B9C31B6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentPeriodicPaymentPrincipal" xlink:label="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_5E1CB7D3353E5262BF333DCA48BA3A6A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_DebtInstrumentPeriodicPaymentPrincipal_5E1CB7D3353E5262BF333DCA48BA3A6A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_0CC6A7E2EE8259508B2A5A70015E46E7" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_0CC6A7E2EE8259508B2A5A70015E46E7" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PaymentsOfFinancingCosts" xlink:label="loc_us-gaap_PaymentsOfFinancingCosts_B94855A8C857544C9CF0F226BC6F2485" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_PaymentsOfFinancingCosts_B94855A8C857544C9CF0F226BC6F2485" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredFinanceCostsNoncurrentNet" xlink:label="loc_us-gaap_DeferredFinanceCostsNoncurrentNet_DF2ABCDF87935DA6A9B8B9D61A9FD373" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_DeferredFinanceCostsNoncurrentNet_DF2ABCDF87935DA6A9B8B9D61A9FD373" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts" xlink:label="loc_us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts_55C4771B145E52449DFE591EE6F4E248" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_DebtRelatedCommitmentFeesAndDebtIssuanceCosts_55C4771B145E52449DFE591EE6F4E248" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_WriteOffOfDeferredDebtIssuanceCost" xlink:label="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_4BFD3C9C8D545A70AF064FF03A8B8A2D" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_WriteOffOfDeferredDebtIssuanceCost_4BFD3C9C8D545A70AF064FF03A8B8A2D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases" xlink:label="loc_us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases_EBE7F1A05C6D58A5B626203F5021B046" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases_EBE7F1A05C6D58A5B626203F5021B046" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentMaturityDate" xlink:label="loc_us-gaap_DebtInstrumentMaturityDate_608F4DFCB3F95075A9659ACF921D4079" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_DebtInstrumentMaturityDate_608F4DFCB3F95075A9659ACF921D4079" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_E6DE12035D995E75A0947E6093982231" xlink:type="locator" />
    <link:definitionArc order="10" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_E6DE12035D995E75A0947E6093982231" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_08051841984F517EAFBCC272FC011703" xlink:type="locator" />
    <link:definitionArc order="11" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_08051841984F517EAFBCC272FC011703" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_IncrementalDebtCommitmentsCapacity" xlink:label="loc_trs_IncrementalDebtCommitmentsCapacity_E45FF9A7F0B1587CBF2ED7DFD1AF35D3" xlink:type="locator" />
    <link:definitionArc order="12" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_trs_IncrementalDebtCommitmentsCapacity_E45FF9A7F0B1587CBF2ED7DFD1AF35D3" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_NetLeverageRatio" xlink:label="loc_trs_NetLeverageRatio_D7E36AD66B0550999BDAF0E9FD3A4802" xlink:type="locator" />
    <link:definitionArc order="13" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_trs_NetLeverageRatio_D7E36AD66B0550999BDAF0E9FD3A4802" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_RequiredprepaymentsundertermloanAfacility" xlink:label="loc_trs_RequiredprepaymentsundertermloanAfacility_2F2FA0783F995B9EB780077897E58F1B" xlink:type="locator" />
    <link:definitionArc order="14" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_trs_RequiredprepaymentsundertermloanAfacility_2F2FA0783F995B9EB780077897E58F1B" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_LetterOfCreditMaximumBorrowingCapacity" xlink:label="loc_trs_LetterOfCreditMaximumBorrowingCapacity_39C0A9DA8A435FE9AAEE0F4245888F4D" xlink:type="locator" />
    <link:definitionArc order="15" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_trs_LetterOfCreditMaximumBorrowingCapacity_39C0A9DA8A435FE9AAEE0F4245888F4D" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_7C3335CEF79759E38CBB6B4B0266A606" xlink:type="locator" />
    <link:definitionArc order="16" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_7C3335CEF79759E38CBB6B4B0266A606" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCredit" xlink:label="loc_us-gaap_LineOfCredit_D9721CBCB85152638DE5C2789A7C6FD1" xlink:type="locator" />
    <link:definitionArc order="17" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_LineOfCredit_D9721CBCB85152638DE5C2789A7C6FD1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_CAEEAF7C94735D35BD8DDEEEBF0F9CDD" xlink:type="locator" />
    <link:definitionArc order="18" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_CAEEAF7C94735D35BD8DDEEEBF0F9CDD" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_LongTermDebtFairValueOfParValue" xlink:label="loc_trs_LongTermDebtFairValueOfParValue_DC2A70DC360055C88CF452ECD33C39D1" xlink:type="locator" />
    <link:definitionArc order="19" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_66ACB4D6DC1B52D6B58608A97E0F0AB1" xlink:to="loc_trs_LongTermDebtFairValueOfParValue_DC2A70DC360055C88CF452ECD33C39D1" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/LongTermDebtDebtTableDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_F5C56B213871565FBDF41BD770573C12" xlink:type="locator" />
    <link:loc xlink:href="trs-20170630.xsd#trs_ScheduleOfDebtInstrumentsTable" xlink:label="loc_trs_ScheduleOfDebtInstrumentsTable_5215F0A6BA1550BDAE8651EB4B64A095" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F5C56B213871565FBDF41BD770573C12" xlink:to="loc_trs_ScheduleOfDebtInstrumentsTable_5215F0A6BA1550BDAE8651EB4B64A095" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="trs-20170630.xsd#trs_PresentationofspinoffcostsAxis" xlink:label="loc_trs_PresentationofspinoffcostsAxis_404BB7E30518534DA646D3EF9D3C24D5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfDebtInstrumentsTable_5215F0A6BA1550BDAE8651EB4B64A095" xlink:to="loc_trs_PresentationofspinoffcostsAxis_404BB7E30518534DA646D3EF9D3C24D5" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DiscontinuedoperationsDomain" xlink:label="loc_trs_DiscontinuedoperationsDomain_7506A8141AC4B4A98ABFA466546E0C5F_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_trs_PresentationofspinoffcostsAxis_404BB7E30518534DA646D3EF9D3C24D5" xlink:to="loc_trs_DiscontinuedoperationsDomain_7506A8141AC4B4A98ABFA466546E0C5F_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DiscontinuedoperationsDomain" xlink:label="loc_trs_DiscontinuedoperationsDomain_C3865C50342C52EF8F14F5154CCDE1CF" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_trs_PresentationofspinoffcostsAxis_404BB7E30518534DA646D3EF9D3C24D5" xlink:to="loc_trs_DiscontinuedoperationsDomain_C3865C50342C52EF8F14F5154CCDE1CF" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentContinuingOperationsMember" xlink:label="loc_us-gaap_SegmentContinuingOperationsMember_68DD1C3374FA566480AC1C416B635B83" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DiscontinuedoperationsDomain_C3865C50342C52EF8F14F5154CCDE1CF" xlink:to="loc_us-gaap_SegmentContinuingOperationsMember_68DD1C3374FA566480AC1C416B635B83" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_BA57F02A6ACD5235B0183A89B0E5183B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfDebtInstrumentsTable_5215F0A6BA1550BDAE8651EB4B64A095" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_BA57F02A6ACD5235B0183A89B0E5183B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_84DDE67A232CFCE9A694A466546E6AE8_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_BA57F02A6ACD5235B0183A89B0E5183B" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_84DDE67A232CFCE9A694A466546E6AE8_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_13167B040A8156638E1C1D53A64394E8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_BA57F02A6ACD5235B0183A89B0E5183B" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_13167B040A8156638E1C1D53A64394E8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_D49490DF4FBE57DE98C2880004CAD456" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_13167B040A8156638E1C1D53A64394E8" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_D49490DF4FBE57DE98C2880004CAD456" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_SeniorSecuredTermLoanMember" xlink:label="loc_trs_SeniorSecuredTermLoanMember_02E2C656255058F5BC83A546E60D190F" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_13167B040A8156638E1C1D53A64394E8" xlink:to="loc_trs_SeniorSecuredTermLoanMember_02E2C656255058F5BC83A546E60D190F" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:label="loc_us-gaap_CreditFacilityAxis_56ADFF4FF64452C3B89096A15DB9F5FB" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfDebtInstrumentsTable_5215F0A6BA1550BDAE8651EB4B64A095" xlink:to="loc_us-gaap_CreditFacilityAxis_56ADFF4FF64452C3B89096A15DB9F5FB" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_46D0B62D1A83CCDEE886A466546E7694_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_56ADFF4FF64452C3B89096A15DB9F5FB" xlink:to="loc_us-gaap_CreditFacilityDomain_46D0B62D1A83CCDEE886A466546E7694_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:label="loc_us-gaap_CreditFacilityDomain_03500DAC3D09540BB94A970D9DCE316C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_56ADFF4FF64452C3B89096A15DB9F5FB" xlink:to="loc_us-gaap_CreditFacilityDomain_03500DAC3D09540BB94A970D9DCE316C" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_TermloanAfacilityMember" xlink:label="loc_trs_TermloanAfacilityMember_AC5F4D4875E15350884E9EBD617D1D20" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_03500DAC3D09540BB94A970D9DCE316C" xlink:to="loc_trs_TermloanAfacilityMember_AC5F4D4875E15350884E9EBD617D1D20" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RevolvingCreditFacilityMember" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_FA2BFF135AC25207B54B21CAA28A9A5C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_03500DAC3D09540BB94A970D9DCE316C" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_FA2BFF135AC25207B54B21CAA28A9A5C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:label="loc_us-gaap_DebtInstrumentAxis_52BCD81232D45A268B82005172DC0749" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfDebtInstrumentsTable_5215F0A6BA1550BDAE8651EB4B64A095" xlink:to="loc_us-gaap_DebtInstrumentAxis_52BCD81232D45A268B82005172DC0749" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_69AD8FD51A4A36251206A466546FE540_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_52BCD81232D45A268B82005172DC0749" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_69AD8FD51A4A36251206A466546FE540_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_D5CD5119BAFB549280B01E4EF9CEED9E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_52BCD81232D45A268B82005172DC0749" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_D5CD5119BAFB549280B01E4EF9CEED9E" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_CreditAgreementMember" xlink:label="loc_trs_CreditAgreementMember_1CC201A0BFDB59A881D3D8D0E59458C1" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_D5CD5119BAFB549280B01E4EF9CEED9E" xlink:to="loc_trs_CreditAgreementMember_1CC201A0BFDB59A881D3D8D0E59458C1" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_ReceivablesFacilityandotherMemberMember" xlink:label="loc_trs_ReceivablesFacilityandotherMemberMember_3FA5E8CA5DA05C07A34EF5657E1048D1" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_D5CD5119BAFB549280B01E4EF9CEED9E" xlink:to="loc_trs_ReceivablesFacilityandotherMemberMember_3FA5E8CA5DA05C07A34EF5657E1048D1" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtAndCapitalLeaseObligations" xlink:label="loc_us-gaap_DebtAndCapitalLeaseObligations_1B13224FA22457759DDF48424C77119C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F5C56B213871565FBDF41BD770573C12" xlink:to="loc_us-gaap_DebtAndCapitalLeaseObligations_1B13224FA22457759DDF48424C77119C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DeferredFinanceCostsNet" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_F6141918CEC3504583478804601708A4" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F5C56B213871565FBDF41BD770573C12" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_F6141918CEC3504583478804601708A4" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtCurrent" xlink:label="loc_us-gaap_DebtCurrent_0C8BC3A1D3885B2593E198E4CE43EA7B" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F5C56B213871565FBDF41BD770573C12" xlink:to="loc_us-gaap_DebtCurrent_0C8BC3A1D3885B2593E198E4CE43EA7B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongTermDebtAndCapitalLeaseObligations" xlink:label="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_EA8C812D05CE54D282E7693D155A42C4" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_F5C56B213871565FBDF41BD770573C12" xlink:to="loc_us-gaap_LongTermDebtAndCapitalLeaseObligations_EA8C812D05CE54D282E7693D155A42C4" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/LongTermDebtLongTermDebtTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/LongTermDebtReceivablesFacilityDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:label="loc_us-gaap_DebtInstrumentLineItems_1F9493175335DC921CC8ACE03EC0634C" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:label="loc_us-gaap_DebtInstrumentTable_C107A7D6C99D9B4F8850ACE03EB6D88B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1F9493175335DC921CC8ACE03EC0634C" xlink:to="loc_us-gaap_DebtInstrumentTable_C107A7D6C99D9B4F8850ACE03EB6D88B" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShortTermDebtTypeAxis" xlink:label="loc_us-gaap_ShortTermDebtTypeAxis_622C200A1BE43BA04FCDACE03EB6026E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_C107A7D6C99D9B4F8850ACE03EB6D88B" xlink:to="loc_us-gaap_ShortTermDebtTypeAxis_622C200A1BE43BA04FCDACE03EB6026E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShortTermDebtTypeDomain" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_A86D5C557663C75A9F7BACE03EB6191B_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_622C200A1BE43BA04FCDACE03EB6026E" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_A86D5C557663C75A9F7BACE03EB6191B_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ShortTermDebtTypeDomain" xlink:label="loc_us-gaap_ShortTermDebtTypeDomain_A86D5C557663C75A9F7BACE03EB6191B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShortTermDebtTypeAxis_622C200A1BE43BA04FCDACE03EB6026E" xlink:to="loc_us-gaap_ShortTermDebtTypeDomain_A86D5C557663C75A9F7BACE03EB6191B" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_OverdraftFacilityMember" xlink:label="loc_trs_OverdraftFacilityMember_D05A91A73D96FFAE3BC5ACE03EB6E9BD" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShortTermDebtTypeDomain_A86D5C557663C75A9F7BACE03EB6191B" xlink:to="loc_trs_OverdraftFacilityMember_D05A91A73D96FFAE3BC5ACE03EB6E9BD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_92A64360EA4A4663D11DACE03EB60315" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_C107A7D6C99D9B4F8850ACE03EB6D88B" xlink:to="loc_us-gaap_RangeAxis_92A64360EA4A4663D11DACE03EB60315" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_3229F90A006C69E3DBD0ACE03EB6B988_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_92A64360EA4A4663D11DACE03EB60315" xlink:to="loc_us-gaap_RangeMember_3229F90A006C69E3DBD0ACE03EB6B988_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_3229F90A006C69E3DBD0ACE03EB6B988" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_92A64360EA4A4663D11DACE03EB60315" xlink:to="loc_us-gaap_RangeMember_3229F90A006C69E3DBD0ACE03EB6B988" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_C56FCE1C62342CEE7381ACE03EC04323" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_3229F90A006C69E3DBD0ACE03EB6B988" xlink:to="loc_us-gaap_MinimumMember_C56FCE1C62342CEE7381ACE03EC04323" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_E9FFF923593DF4200778ACE03EC0F3FC" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_3229F90A006C69E3DBD0ACE03EB6B988" xlink:to="loc_us-gaap_MaximumMember_E9FFF923593DF4200778ACE03EC0F3FC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeAxis" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_0E4B2B42F1B8F365597DACE03EC03783" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_C107A7D6C99D9B4F8850ACE03EB6D88B" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_0E4B2B42F1B8F365597DACE03EC03783" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_C85579DF08BCC11DE17FACE03EC0F937_default" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_0E4B2B42F1B8F365597DACE03EC03783" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_C85579DF08BCC11DE17FACE03EC0F937_default" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LongtermDebtTypeDomain" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_C85579DF08BCC11DE17FACE03EC0F937" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_0E4B2B42F1B8F365597DACE03EC03783" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_C85579DF08BCC11DE17FACE03EC0F937" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SecuredDebtMember" xlink:label="loc_us-gaap_SecuredDebtMember_14833C73B0397CCDAE30ACE03EC09B68" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_C85579DF08BCC11DE17FACE03EC0F937" xlink:to="loc_us-gaap_SecuredDebtMember_14833C73B0397CCDAE30ACE03EC09B68" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_SecuredDebtMaximumBorrowingCapacity" xlink:label="loc_trs_SecuredDebtMaximumBorrowingCapacity_A60157BDD35B8AF54FE4ACE03EC085E0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1F9493175335DC921CC8ACE03EC0634C" xlink:to="loc_trs_SecuredDebtMaximumBorrowingCapacity_A60157BDD35B8AF54FE4ACE03EC085E0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_8FCEF7BA6F1D7E02CAA6ACE03EC0ABF6" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1F9493175335DC921CC8ACE03EC0634C" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_8FCEF7BA6F1D7E02CAA6ACE03EC0ABF6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SecuredDebt" xlink:label="loc_us-gaap_SecuredDebt_E5C43E246DF2D1365D42ACE03EC016D0" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1F9493175335DC921CC8ACE03EC0634C" xlink:to="loc_us-gaap_SecuredDebt_E5C43E246DF2D1365D42ACE03EC016D0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount" xlink:label="loc_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_3C5207FAA656CF58E63EACE03EC058F2" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1F9493175335DC921CC8ACE03EC0634C" xlink:to="loc_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_3C5207FAA656CF58E63EACE03EC058F2" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_ReceivablesFacililtyDebtAggregateCosts" xlink:label="loc_trs_ReceivablesFacililtyDebtAggregateCosts_45DD9F2BB131E56EB688ACE03EC0A7E6" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1F9493175335DC921CC8ACE03EC0634C" xlink:to="loc_trs_ReceivablesFacililtyDebtAggregateCosts_45DD9F2BB131E56EB688ACE03EC0A7E6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DebtInstrumentMaturityDate" xlink:label="loc_us-gaap_DebtInstrumentMaturityDate_6A439E4CE64B63EB66C7ACE03EC018AB" xlink:type="locator" />
    <link:definitionArc order="6" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1F9493175335DC921CC8ACE03EC0634C" xlink:to="loc_us-gaap_DebtInstrumentMaturityDate_6A439E4CE64B63EB66C7ACE03EC018AB" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_DebtInstrumentUnusedBorrowingCapacityFeePercentage" xlink:label="loc_trs_DebtInstrumentUnusedBorrowingCapacityFeePercentage_6B57335A5A52230FBF0BACE03EC0BA83" xlink:type="locator" />
    <link:definitionArc order="7" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1F9493175335DC921CC8ACE03EC0634C" xlink:to="loc_trs_DebtInstrumentUnusedBorrowingCapacityFeePercentage_6B57335A5A52230FBF0BACE03EC0BA83" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_AverageliquidationperiodReceivablespool" xlink:label="loc_trs_AverageliquidationperiodReceivablespool_05081F402F123753F220ACE03EC04166" xlink:type="locator" />
    <link:definitionArc order="8" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1F9493175335DC921CC8ACE03EC0634C" xlink:to="loc_trs_AverageliquidationperiodReceivablespool_05081F402F123753F220ACE03EC04166" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_AverageDiscountRateReceivablesFacility" xlink:label="loc_trs_AverageDiscountRateReceivablesFacility_DE21BFBA0EA8AE939178ACE03EC09D4A" xlink:type="locator" />
    <link:definitionArc order="9" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_1F9493175335DC921CC8ACE03EC0634C" xlink:to="loc_trs_AverageDiscountRateReceivablesFacility_DE21BFBA0EA8AE939178ACE03EC09D4A" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/NewAccountingPronouncements" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/NewAccountingPronouncementsNewAccountingPronouncementsDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_2B63E50DD66B5334A9A4B3AE7EB24626" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable" xlink:label="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_42D0DA8E5D1E5525A040E4FB7688ADA2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_2B63E50DD66B5334A9A4B3AE7EB24626" xlink:to="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_42D0DA8E5D1E5525A040E4FB7688ADA2" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:label="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_E5EE9C4E4AE55AA0A6EA9E098937761E" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleTable_42D0DA8E5D1E5525A040E4FB7688ADA2" xlink:to="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_E5EE9C4E4AE55AA0A6EA9E098937761E" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_9C168E00665AA9752A95A55679A56109_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_E5EE9C4E4AE55AA0A6EA9E098937761E" xlink:to="loc_us-gaap_TypeOfAdoptionMember_9C168E00665AA9752A95A55679A56109_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:label="loc_us-gaap_TypeOfAdoptionMember_37C9AAE756C45BBFAE32474507D0B4FC" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_E5EE9C4E4AE55AA0A6EA9E098937761E" xlink:to="loc_us-gaap_TypeOfAdoptionMember_37C9AAE756C45BBFAE32474507D0B4FC" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_NewAccountingPronouncementMember" xlink:label="loc_us-gaap_NewAccountingPronouncementMember_51D6CCF99D5C59C29A06A1E0803AA1D0" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TypeOfAdoptionMember_37C9AAE756C45BBFAE32474507D0B4FC" xlink:to="loc_us-gaap_NewAccountingPronouncementMember_51D6CCF99D5C59C29A06A1E0803AA1D0" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_26D3A1133F2859558A6C6CB1F111249A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NewAccountingPronouncementsOrChangeInAccountingPrincipleLineItems_2B63E50DD66B5334A9A4B3AE7EB24626" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense_26D3A1133F2859558A6C6CB1F111249A" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/OtherComprehensiveIncomeLossDetails" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/OtherComprehensiveIncomeLossNotes" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/OtherComprehensiveIncomeLossTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/PropertyAndEquipmentNet" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/PropertyAndEquipmentNetDepreciationExpenseTableDetails" xlink:type="extended">
    <link:loc xlink:href="trs-20170630.xsd#trs_DepreciationExpenseLineItems" xlink:label="loc_trs_DepreciationExpenseLineItems_4DC15575DD0E511B88D0440A22EA66AB" xlink:type="locator" />
    <link:loc xlink:href="trs-20170630.xsd#trs_ScheduleOfDepreciationExpenseTable" xlink:label="loc_trs_ScheduleOfDepreciationExpenseTable_495C6E2E0E9E53A38AC9B69DD2B6A2C2" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_trs_DepreciationExpenseLineItems_4DC15575DD0E511B88D0440A22EA66AB" xlink:to="loc_trs_ScheduleOfDepreciationExpenseTable_495C6E2E0E9E53A38AC9B69DD2B6A2C2" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationAxis" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_7F8629BE14B8561B9939C5BB0B15474C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfDepreciationExpenseTable_495C6E2E0E9E53A38AC9B69DD2B6A2C2" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_7F8629BE14B8561B9939C5BB0B15474C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_A5F8A3DD66D0EC657D07A466566457CE_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_7F8629BE14B8561B9939C5BB0B15474C" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_A5F8A3DD66D0EC657D07A466566457CE_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_IncomeStatementLocationDomain" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_1772683DD29D5856975E7BBB53E0D45C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_7F8629BE14B8561B9939C5BB0B15474C" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_1772683DD29D5856975E7BBB53E0D45C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CostOfSalesMember" xlink:label="loc_us-gaap_CostOfSalesMember_30BE46BE2805571AAB9FD6F865C9B88B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_1772683DD29D5856975E7BBB53E0D45C" xlink:to="loc_us-gaap_CostOfSalesMember_30BE46BE2805571AAB9FD6F865C9B88B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpensesMember" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_BB047740D7A7578BBDC81B5F186680A2" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_1772683DD29D5856975E7BBB53E0D45C" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpensesMember_BB047740D7A7578BBDC81B5F186680A2" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementOperatingActivitiesSegmentAxis" xlink:label="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_67631D0183E651289C47E433DF65BAAD" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_trs_ScheduleOfDepreciationExpenseTable_495C6E2E0E9E53A38AC9B69DD2B6A2C2" xlink:to="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_67631D0183E651289C47E433DF65BAAD" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentOperatingActivitiesDomain" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_EC94D9628347D917C512A46656666814_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_67631D0183E651289C47E433DF65BAAD" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_EC94D9628347D917C512A46656666814_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentOperatingActivitiesDomain" xlink:label="loc_us-gaap_SegmentOperatingActivitiesDomain_F30BB70A4731555787555F6ABAC3131B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementOperatingActivitiesSegmentAxis_67631D0183E651289C47E433DF65BAAD" xlink:to="loc_us-gaap_SegmentOperatingActivitiesDomain_F30BB70A4731555787555F6ABAC3131B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentContinuingOperationsMember" xlink:label="loc_us-gaap_SegmentContinuingOperationsMember_0626922382DF5BE1B6A2B17DA6EB6EDA" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentOperatingActivitiesDomain_F30BB70A4731555787555F6ABAC3131B" xlink:to="loc_us-gaap_SegmentContinuingOperationsMember_0626922382DF5BE1B6A2B17DA6EB6EDA" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_Depreciation" xlink:label="loc_us-gaap_Depreciation_6BA5B6B4B7A3599C8C21E4C0B6236B10" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_trs_DepreciationExpenseLineItems_4DC15575DD0E511B88D0440A22EA66AB" xlink:to="loc_us-gaap_Depreciation_6BA5B6B4B7A3599C8C21E4C0B6236B10" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/PropertyAndEquipmentNetPropertyAndEquipmentTableDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_0E0207BC4BAD500B96DCED4E4E2F7783" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9FC1E46B89B1547DB16CA594C1AB81B9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_0E0207BC4BAD500B96DCED4E4E2F7783" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9FC1E46B89B1547DB16CA594C1AB81B9" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6FBF798EAF1A5F1FA36434CE08827EBE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_9FC1E46B89B1547DB16CA594C1AB81B9" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6FBF798EAF1A5F1FA36434CE08827EBE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_A2AEF4B53D08DDAAAF8CA466555693AD_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6FBF798EAF1A5F1FA36434CE08827EBE" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_A2AEF4B53D08DDAAAF8CA466555693AD_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BC7A8E76E6B35F54827EDCD6C88909C9" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_6FBF798EAF1A5F1FA36434CE08827EBE" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BC7A8E76E6B35F54827EDCD6C88909C9" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_LandAndLandImprovementsMember" xlink:label="loc_us-gaap_LandAndLandImprovementsMember_D31717B91F385561BF5204737C3ADCC5" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BC7A8E76E6B35F54827EDCD6C88909C9" xlink:to="loc_us-gaap_LandAndLandImprovementsMember_D31717B91F385561BF5204737C3ADCC5" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_BuildingMember" xlink:label="loc_us-gaap_BuildingMember_E425302CD11B5C97B3BADCD43A01DB34" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BC7A8E76E6B35F54827EDCD6C88909C9" xlink:to="loc_us-gaap_BuildingMember_E425302CD11B5C97B3BADCD43A01DB34" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MachineryAndEquipmentMember" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_CCE0FAD5266C53D7887C478C259CDB19" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_BC7A8E76E6B35F54827EDCD6C88909C9" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_CCE0FAD5266C53D7887C478C259CDB19" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentGross_DB7E55B9048E5D10A71C7E861628DD27" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_0E0207BC4BAD500B96DCED4E4E2F7783" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentGross_DB7E55B9048E5D10A71C7E861628DD27" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:label="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_C4608FB4C63E50A7B8DF01ECFDA10038" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_0E0207BC4BAD500B96DCED4E4E2F7783" xlink:to="loc_us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_C4608FB4C63E50A7B8DF01ECFDA10038" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_B813D726979453E19BA860D15F8D6AF6" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_0E0207BC4BAD500B96DCED4E4E2F7783" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_B813D726979453E19BA860D15F8D6AF6" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/PropertyAndEquipmentNetTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SegmentInformation" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SegmentInformationDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_9140DF8306225CC480395207E7EC3CB3" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_85F6CCCA145159499BA2303A0E435791" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_9140DF8306225CC480395207E7EC3CB3" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_85F6CCCA145159499BA2303A0E435791" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_C0596E07BBC55476894E47BDEC5E139B" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_85F6CCCA145159499BA2303A0E435791" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_C0596E07BBC55476894E47BDEC5E139B" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_067CD03283ABF6D80FFFA466558A3416_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_C0596E07BBC55476894E47BDEC5E139B" xlink:to="loc_us-gaap_SegmentDomain_067CD03283ABF6D80FFFA466558A3416_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SegmentDomain" xlink:label="loc_us-gaap_SegmentDomain_07A6A054613A5701AF4BF857274E1537" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_C0596E07BBC55476894E47BDEC5E139B" xlink:to="loc_us-gaap_SegmentDomain_07A6A054613A5701AF4BF857274E1537" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_PackagingReportableSegmentMember" xlink:label="loc_trs_PackagingReportableSegmentMember_70EF05C25F2E538A8C9C1E5E4F4DDE96" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_07A6A054613A5701AF4BF857274E1537" xlink:to="loc_trs_PackagingReportableSegmentMember_70EF05C25F2E538A8C9C1E5E4F4DDE96" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_AerospaceDefenseReportableSegmentMember" xlink:label="loc_trs_AerospaceDefenseReportableSegmentMember_D44B4F5ACA155DBB8683A3527386C0C8" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_07A6A054613A5701AF4BF857274E1537" xlink:to="loc_trs_AerospaceDefenseReportableSegmentMember_D44B4F5ACA155DBB8683A3527386C0C8" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_EnergyReportableSegmentMember" xlink:label="loc_trs_EnergyReportableSegmentMember_3209D16CC2705CC68FFDC3EC365A1769" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_07A6A054613A5701AF4BF857274E1537" xlink:to="loc_trs_EnergyReportableSegmentMember_3209D16CC2705CC68FFDC3EC365A1769" xlink:type="arc" />
    <link:loc xlink:href="trs-20170630.xsd#trs_EngineeredComponentsReportableSegmentMember" xlink:label="loc_trs_EngineeredComponentsReportableSegmentMember_9A6DF4EA18B75C6293F23C4EC5081791" xlink:type="locator" />
    <link:definitionArc order="4" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_07A6A054613A5701AF4BF857274E1537" xlink:to="loc_trs_EngineeredComponentsReportableSegmentMember_9A6DF4EA18B75C6293F23C4EC5081791" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_CorporateNonSegmentMember" xlink:label="loc_us-gaap_CorporateNonSegmentMember_19C6DCCDFD6C5FEF9641A908E1F6D922" xlink:type="locator" />
    <link:definitionArc order="5" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_07A6A054613A5701AF4BF857274E1537" xlink:to="loc_us-gaap_CorporateNonSegmentMember_19C6DCCDFD6C5FEF9641A908E1F6D922" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SalesRevenueNet" xlink:label="loc_us-gaap_SalesRevenueNet_4424EEFF475450199CDFAA3E9E2ABB8A" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_9140DF8306225CC480395207E7EC3CB3" xlink:to="loc_us-gaap_SalesRevenueNet_4424EEFF475450199CDFAA3E9E2ABB8A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:label="loc_us-gaap_OperatingIncomeLoss_69016E5122625F11BCFE31BDB749694B" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_9140DF8306225CC480395207E7EC3CB3" xlink:to="loc_us-gaap_OperatingIncomeLoss_69016E5122625F11BCFE31BDB749694B" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SegmentInformationTables" xlink:type="extended" />
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SubsequentEventDetails" xlink:type="extended">
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventLineItems" xlink:label="loc_us-gaap_SubsequentEventLineItems_1E3881B2AA9058C49C44A9EF55C4BD37" xlink:type="locator" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventTable" xlink:label="loc_us-gaap_SubsequentEventTable_E7A76CAA42B652088BFBF7609B1DBB39" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_1E3881B2AA9058C49C44A9EF55C4BD37" xlink:to="loc_us-gaap_SubsequentEventTable_E7A76CAA42B652088BFBF7609B1DBB39" xlink:type="arc" xbrldt:closed="true" xbrldt:contextElement="segment" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_E8B827F01B4955A4A2CD84357CADDDC8" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_E7A76CAA42B652088BFBF7609B1DBB39" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_E8B827F01B4955A4A2CD84357CADDDC8" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_75F97B08BCC10373525BA466561F23E2_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_E8B827F01B4955A4A2CD84357CADDDC8" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_75F97B08BCC10373525BA466561F23E2_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_BABF42498DA5522FB5F2C7C961203C30" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_E8B827F01B4955A4A2CD84357CADDDC8" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_BABF42498DA5522FB5F2C7C961203C30" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:label="loc_us-gaap_InterestRateSwapMember_A62DAC3AF8DE5B1E8C75C4612BBCE964" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_BABF42498DA5522FB5F2C7C961203C30" xlink:to="loc_us-gaap_InterestRateSwapMember_A62DAC3AF8DE5B1E8C75C4612BBCE964" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeAxis" xlink:label="loc_us-gaap_RangeAxis_953683C2ABF35C19A19D4B7C62A6966A" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_E7A76CAA42B652088BFBF7609B1DBB39" xlink:to="loc_us-gaap_RangeAxis_953683C2ABF35C19A19D4B7C62A6966A" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_3861123A3F773FBFA5F3A4665620AF9A_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RangeAxis_953683C2ABF35C19A19D4B7C62A6966A" xlink:to="loc_us-gaap_RangeMember_3861123A3F773FBFA5F3A4665620AF9A_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_RangeMember" xlink:label="loc_us-gaap_RangeMember_4D80FF0740415991A8331D5383D1FF9C" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RangeAxis_953683C2ABF35C19A19D4B7C62A6966A" xlink:to="loc_us-gaap_RangeMember_4D80FF0740415991A8331D5383D1FF9C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MinimumMember" xlink:label="loc_us-gaap_MinimumMember_999095990ACE520FB7A834A629B8C533" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_4D80FF0740415991A8331D5383D1FF9C" xlink:to="loc_us-gaap_MinimumMember_999095990ACE520FB7A834A629B8C533" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_MaximumMember" xlink:label="loc_us-gaap_MaximumMember_55B94ED909EB520C8414BC098D50F17C" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RangeMember_4D80FF0740415991A8331D5383D1FF9C" xlink:to="loc_us-gaap_MaximumMember_55B94ED909EB520C8414BC098D50F17C" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventTypeAxis" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_A37007D33E3050018CEA91423C13F5ED" xlink:type="locator" />
    <link:definitionArc order="3" xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_E7A76CAA42B652088BFBF7609B1DBB39" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_A37007D33E3050018CEA91423C13F5ED" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_2982545CC51C8280BBF3A46656215CE5_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_A37007D33E3050018CEA91423C13F5ED" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_2982545CC51C8280BBF3A46656215CE5_0CBA461AF5E35B7AB177BACF211ED4DE" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventTypeDomain" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_8E55A5536A64526380BD5C5690DF2752" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_A37007D33E3050018CEA91423C13F5ED" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_8E55A5536A64526380BD5C5690DF2752" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_SubsequentEventMember" xlink:label="loc_us-gaap_SubsequentEventMember_FE71F230B4835347B2F335267E4EB235" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_8E55A5536A64526380BD5C5690DF2752" xlink:to="loc_us-gaap_SubsequentEventMember_FE71F230B4835347B2F335267E4EB235" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.fasb.org/us-gaap/2016/elts/us-gaap-2016-01-31.xsd#us-gaap_DerivativeFixedInterestRate" xlink:label="loc_us-gaap_DerivativeFixedInterestRate_0B2AEE653ADE500D8185E99066DF25D6" xlink:type="locator" />
    <link:definitionArc order="1" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_1E3881B2AA9058C49C44A9EF55C4BD37" xlink:to="loc_us-gaap_DerivativeFixedInterestRate_0B2AEE653ADE500D8185E99066DF25D6" xlink:type="arc" />
    <link:loc xlink:href="http://xbrl.sec.gov/invest/2013/invest-2013-01-31.xsd#invest_DerivativeNotionalAmount" xlink:label="loc_invest_DerivativeNotionalAmount_474C4F084D7F510BA716779B672E1C75" xlink:type="locator" />
    <link:definitionArc order="2" xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_1E3881B2AA9058C49C44A9EF55C4BD37" xlink:to="loc_invest_DerivativeNotionalAmount_474C4F084D7F510BA716779B672E1C75" xlink:type="arc" />
  </link:definitionLink>
  <link:definitionLink xlink:role="http://www.trimascorp.com/role/SubsequentEventNotes" xlink:type="extended" />
</link:linkbase>





