Appetiser in tin found by primate (6)
I believe the answer is:
canape
'appetiser' is the definition.
(canapes are served as appetisers)
'tin found by primate' is the wordplay.
'tin' becomes 'can' (synonyms).
'found by' is a charade indicator (letters next to each other).
'primate' becomes 'ape' (ape is a kind of primate).
'can'+'ape'='CANAPE'
'in' acts as a link.
(Other definitions for canape that I've seen before include "Small piece of bread or biscuit with savoury spread" , "Item of party food" , "Savoury nibble offered at posh parties" , "Piece of finger food" , "Small appetising savoury" .)