Definition from Wiktionary, the free dictionary
scowl (plural scowls)
- The wrinkling of the brows or face in frowning; the expression of displeasure, sullenness, or discontent in the countenance; an angry frown.
- Hence, gloom; dark or threatening aspect.
Derived terms 
wrinkling of the brows or face
- (intransitive) To wrinkle the brows, as in frowning or displeasure; to put on a frowning look; to look sour, sullen, severe, or angry.
- She scowled and frowned with froward countenance.
- (intransitive, by extension) To look gloomy, dark, or threatening; to lower.
- The scowling heavens.
- (intransitive) To look at or repel with a scowl or a frown.
- to scowl a rival into submission
- (transitive) To express by a scowl.
- to scowl defiance
to wrinkle the brows
to look at or repel with a scowl or a frown