half-wit vs retard

half-wit and retard both are nouns.

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

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

Other synonyms of half-wit include changeling, cretin, idiot, imbecile, moron.

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

half-wit (verb)	retard (verb)
	lose velocity; move more slowly
	cause to move more slowly or operate at a slower rate
	slow the growth or development of
	be delayed