Pouting grimace (4)
I believe the answer is:
moue
'pouting grimace' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for moue that I've seen before include "Disdainful pout" , "Face" , "Expression of disdain" , "Insolent pout" , "Sulky expression" .)