Gin with battered fish (7)
I believe the answer is:
whiting
'fish' is the definition.
(whiting is a kind of fish)
'gin with battered' is the wordplay.
'battered' indicates anagramming the letters.
'gin'+'with'='ginwith'
'ginwith' is an anagram of 'WHITING'.
(Other definitions for whiting that I've seen before include "North Atlantic food fish" , "Edible marine fish" , "[SOMETHING FISHY]" , "Small sea fish or ground chalk for painting" , "Small fish related to cod" .)