Grumpy expressions (6)
I believe the answer is:
scowls
'grumpy expressions' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for scowls that I've seen before include "forbidding looks" , "Bad-tempered frowns" , "Gives black looks" , "Wrinkles forehead in disapproval" , "Frowns with displeasure" .)