scowl vs lour

scowl is a noun but lour is not a noun.

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

As verbs, lour is a hypernym of scowl; that is, lour is a word with a broader meaning than scowl:

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

Other hypernyms of scowl include frown, glower, lower.

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

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