frown vs scowl

frown and scowl both are nouns.

Word	Noun	Adjective	Verb	Adverb
frown	Yes	No	Yes	No
scowl	Yes	No	Yes	No

As nouns, frown and scowl are synonyms defined as:

As verbs, scowl is a hyponym of frown; that is, scowl is a word with a more specific, narrower meaning than frown:

frown: look angry or sullen, wrinkle one's forehead, as if to signal disapproval
scowl: frown with displeasure

frown (noun)	scowl (noun)
a facial expression of dislike or displeasure	a facial expression of dislike or displeasure

frown (verb)	scowl (verb)
look angry or sullen, wrinkle one's forehead, as if to signal disapproval	frown with displeasure