Beef or game (6)
I believe the answer is:
grouse
I believe this is a double definition.
'beef' is the first definition.
(both can mean to complain)
'game?' is the second definition.
(I know that grouse is a type of game bird)
'or' is the link.
(Other definitions for grouse that I've seen before include "Game bird - beef" , "The complaint of a gamebird" , "Complain like gamebird" , "No shooting it before 12 August" , "Gripe; game bird" .)