half-witted vs slow-witted

half-witted and slow-witted both are adjectives.

Word	Noun	Adjective	Verb	Adverb
half-witted	No	Yes	No	No
slow-witted	No	Yes	No	No

As adjectives, half-witted and slow-witted are synonyms defined as:

Other synonyms of half-witted include backward, feebleminded.

half-witted (adjective)	slow-witted (adjective)
retarded in intellectual development	retarded in intellectual development