Grouch's look (5)
I believe the answer is:
scowl
'grouch's look' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for scowl that I've seen before include "Bad-tempered expression" , "Look angry" , "Angrily frown" , "dirty look" , "Gloomy or threatening expression" .)