Golfer's warning shout (4)
I believe the answer is:
fore
'golfer's warning shout' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for fore that I've seen before include "At the bow" , "Not aft" , "Golfer's warning shout" , "The front part of a ship" , "Golfer's shouted warning" .)