Frown, glower (5)
I believe the answer is:
scowl
This clue is a double definition.
'frown' is the first definition.
(I know that frown can be written as scowl)
'glower' is the second definition.
(I know this)
(Other definitions for scowl that I've seen before include "Frown with displeasure" , "Angry facial expression" , "Look threatening" , "Angry frown" , "Glare" .)