half-wit vs doofus

half-wit and doofus both are nouns.

Word	Noun	Adjective	Verb	Adverb
half-wit	Yes	No	No	No
doofus	Yes	No	No	No

As nouns, half-wit and doofus are synonyms defined as:

Other synonyms of half-wit include dimwit, nitwit.

half-wit (noun)	doofus (noun)
a stupid incompetent person	a stupid incompetent person
a person of subnormal intelligence