Potent green anise-flavoured alcoholic drink originally made from wormwood (8)
I believe the answer is:
absinthe
(Other definitions for absinthe that I've seen before include "Bitter liqueur" , "Green aniseed liqueur" , "Potent aniseed-flavoured drink" , "Strong green liqueur, lethal when made with wormwood" , "Strong green alcoholic drink" .)