Sailor to do wrong when given the drink (8)
I believe the answer is:
absinthe
'drink' is the definition.
(absinthe is a kind of drink)
'sailor to do wrong when given the' is the wordplay.
'sailor' becomes 'ab' (abbreviation for able seaman).
'to do wrong' becomes 'sin' (to sin is to do wrong or act badly).
'when given' means one lot of letters go next to another.
'ab'+'sin'+'the'='ABSINTHE'
(Other definitions for absinthe that I've seen before include "Green aniseed liqueur" , "Liqueur - the basin (anag)" , "Potent green gin-type liquor - wormwood" , "Strong liquour in the basin?" , "Potent aniseed-flavoured drink" .)