noun
also cu·ma·rin ˈk(y)ümərə̇n, -ˌrēn
( -s )
Etymology: French coumarine, from coumarou + -ine
: a toxic white crystalline lactone C 9 H 6 O 2 with an odor of new-mown hay that is found in many plants (as the tonka bean and clover), is made synthetically, and is used in perfumery and soap, in the synthesis of dicoumarol, and formerly in flavoring; 1,2-benzo-pyrone ; also : any derivative (as umbelliferone) of this compound