Contract could be a game of cards (7)
I believe the answer is:
abridge
'contract' is the definition.
(synonyms)
'a game of cards' is the wordplay.
'game of cards' becomes 'bridge' (bridge is a card game).
'a'+'bridge'='ABRIDGE'
'could be' is the link.
(Other definitions for abridge that I've seen before include "Abbreviate, contract" , "Make short work" , "Shorten (a literary work)" , "Shorten, a book say, without losing the sense" , "Shorten by using fewer words" .)