amentia vs subnormality

amentia and subnormality both are nouns.

Word	Noun	Adjective	Verb	Adverb
amentia	Yes	No	No	No
subnormality	Yes	No	No	No

As nouns, subnormality is a hypernym of amentia; that is, subnormality is a word with a broader meaning than amentia:

Other hypernyms of amentia include backwardness, mental retardation, retardation, slowness.

amentia (noun)	subnormality (noun)
extreme mental retardation	lack of normal development of intellectual capacities
	the state of being less than normal (especially with respect to intelligence)