Turkey possibly caught fish (5)
I believe the answer is:
trout
'fish' is the definition.
(trout is a kind of fish)
'turkey possibly caught' is the wordplay.
'turkey' becomes 'tr' (I've seen this in other clues).
'possibly caught' becomes 'out' (I've seen this before).
'tr'+'out'='TROUT'
(Other definitions for trout that I've seen before include "Commonly caught fish" , "Tasty fish, brown or rainbow" , "Schubert Quintet?" , "one of a noted quintet" , "old bag" .)