Forehead (4)
I believe the answer is:
brow
'forehead' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for brow that I've seen before include "Forehead, sometimes knitted" , "Top of hill - part of face" , "Forehead or hill summit" , "Surprised one can raise this" , "Forehead - hilltop" .)