abnormal vs subnormal

abnormal is not a noun while subnormal is a noun.

Word	Noun	Adjective	Verb	Adverb
abnormal	No	Yes	No	No
subnormal	Yes	Yes	No	No

abnormal (noun)	subnormal (noun)
	a person of less than normal intelligence

abnormal (adjective)	subnormal (adjective)
not normal; not typical or usual or regular or conforming to a norm	below normal or average
departing from the normal in e.g. intelligence and development
much greater than the normal