ˌhīəˈsīəˌmēn, -_mə̇n noun
( -s )
Etymology: German hyoscyamin, from New Latin Hyoscyamus (genus that produces it) + German -in -ine
: a poisonous crystalline alkaloid C 17 H 23 NO 3 known in three optically isomeric forms : the ester of tropine and tropic acid ; especially : the levorotatory form of this alkaloid that readily yields the racemic form atropine (as by treatment with alkali), that occurs in henbane, belladonna, and various other plants of the family Solanaceae (as species of Datura ), and that is more active than atropine in most pharmacological effects and is used similarly (as in sedation and in relieving spasms)