Copy card game, briefly (4)
I believe the answer is:
crib
I believe this clue is a double definition.
'copy' is the first definition.
(crib can mean to copy from another source)
'card game briefly' is the second definition.
(short for cribbage; 'briefly' suggests a short form)
(Other definitions for crib that I've seen before include "Plagiarise - cot" , "Steal the work" , "which animals inhabit" , "Cheat by copying - card game" , "urban dwelling" .)