Card game — bridge (7)
I believe the answer is:
pontoon
I believe this clue is a double definition.
'card game' is the first definition.
(I've seen this before)
'bridge' is the second definition.
(pontoon bridge is a kind of bridge)
(Other definitions for pontoon that I've seen before include "Lighter" , "'Flat-bottomed boat, card game and Mayo town (7)'" , "variety of bridge" , "It spans" , "Vingt-et-un" .)