absinthium

noun
ab·​sin·​thi·​um | \ ab-ˈsin(t)-thē-əm How to pronounce absinthium (audio) \
plural absinthium

Medical Definition of absinthium

1 : wormwood
2a : the dried leaves and flowering tops of a common wormwood (Artemisia absinthium) once used as a bitter tonic and stomachic
b : oil of wormwood used as an ingredient of absinthe