Fish amidst rotten chips (5)
I believe the answer is:
tench
'fish' is the definition.
(tench is a kind of fish)
'amidst rotten chips' is the wordplay.
'amidst' indicates a hidden word (the answer appears amidst the letters of the clue).
'TENCH' is hidden within 'rotten chips'.
(Other definitions for tench that I've seen before include "Coarse fish" , "catch" , "Fish of the carp family" , "Swimmer" , "Freshwater fish" .)