Card game; boast (4)
I believe the answer is:
brag
I believe this clue is a double definition.
'card game' is the first definition.
(brag is an old card game)
'boast' is the second definition.
(I know that boast can be written as brag)
(Other definitions for brag that I've seen before include "Show off, crow" , "Boast, crow" , "Card game, like poker" , "Idle talk" , "Talk boastfully" .)