Fish for fete’s sandwiches (4)
I believe the answer is:
orfe
'fish' is the definition.
(I've seen this before)
'for fete's sandwiches' is the wordplay.
'sandwiches' indicates the answer is hidden within the clue (the answer is sandwiched in by the clue).
'ORFE' is hidden within 'for fetes'.
(Other definitions for orfe that I've seen before include "Fish of carp family; rhymes with quayside" , "swimmer" , "Silvery freshwater fish of carp family" .)