soft-witted vs stupid

soft-witted is not a noun while stupid is a noun.

Word	Noun	Adjective	Verb	Adverb
soft-witted	No	Yes	No	No
stupid	Yes	Yes	No	No

soft-witted (noun)	stupid (noun)
	a person who is not very bright

soft-witted (adjective)	stupid (adjective)
(of especially persons) lacking sense or understanding or judgment	lacking or marked by lack of intellectual acuity
	lacking intelligence
	in a state of mental numbness especially as resulting from shock