Glowering (8)
I believe the answer is:
scowling
'glowering' is the definition.
(scowling is a kind of glowering)
This is all the clue.
(Other definitions for scowling that I've seen before include "glowering" , "looking displeased" , "Lowering" , "Frowning with displeasure" , "looking unhappy?" .)