Goal's beginning to stir up game (6)
I believe the answer is:
grouse
'game' is the definition.
(I've seen this before)
'goal's beginning to stir up' is the wordplay.
'beginning to' indicates taking the first letters.
'stir up' becomes 'rouse' (I've seen this before).
The initial letter of 'goals' is 'g'.
'g'+'rouse'='GROUSE'
(Other definitions for grouse that I've seen before include "Complain like game bird" , "Bellyache" , "Complain pettily" , "See game bird" , "The complaint of a gamebird" .)