Cut card or fish (8)
I believe the answer is:
skipjack
'fish' is the definition.
(skipjack is a kind of fish)
'cut card' is the wordplay.
'cut' becomes 'skip' (synonyms).
'card' becomes 'jack' (type of playing card).
'skip'+'jack'='SKIPJACK'
'or' acts as a link.
(Other definitions for skipjack that I've seen before include "sailing boat" , "Food fish" , "Type of tuna" .)