Frowns (6)
I believe the answer is:
scowls
'frowns' is the definition.
(scowling is a kind of frowning)
This is all the clue.
(Other definitions for scowls that I've seen before include "Frowns with displeasure" , "Gives black looks" , "Angry frowns" , "Furrows forehead in bad humour" , "Bad-tempered frowns" .)