Nonsense about drink (gin) (8)
I believe the answer is:
claptrap
'nonsense' is the definition.
(informal term meaning nonsense or rubbish)
'about drink gin' is the wordplay.
'about' becomes 'c' (circa).
'drink' becomes 'lap' (lap can mean to drink).
'gin' becomes 'trap' (I've seen this in another clue).
'c'+'lap'+'trap'='CLAPTRAP'
(Other definitions for claptrap that I've seen before include "Contrived but foolish talk" , "Pretentious rot" , "Empty words" , "Pretentious talk or nonsense" , "Applaud snare? - that's pretentious nonsense" .)