Game group off looking for openings (4)
I believe the answer is:
golf
'game' is the definition.
(golf is a game)
'group off looking for openings' is the wordplay.
'openings' indicates taking the first letters (I've seen 'opening' mean this).
The first letters of 'group off looking for' is 'GOLF'.
(Other definitions for golf that I've seen before include "Something played" , "Comms code for G" , "Game with clubs" , "Flog the game badly" , "Sport with bunkers" .)