Liqueur drunk neat: it’s taken with tablet (8)
I believe the answer is:
anisette
'liqueur' is the definition.
(anisette is a kind of liqueur)
'drunk neat it's taken with tablet' is the wordplay.
'drunk' is an anagram indicator.
'taken with' means one lot of letters go next to another.
'tablet' becomes 'e' (E can mean ecstasy or an ecstasy tablet).
'neat'+'its'='neatits'
'neatits' with letters rearranged gives 'anisett'.
'anisett'+'e'='ANISETTE'
(Other definitions for anisette that I've seen before include "Liqueur flavoured with seeds" , "Liqueur with flavour of liquorice" , "Liquorice-flavoured liqueur" , "Aromatic cordial drink" , "Type of highly-flavoured liqueur" .)