subnormality vs abnormalcy

subnormality and abnormalcy both are nouns.

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

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

subnormality: the state of being less than normal (especially with respect to intelligence)
abnormalcy: an abnormal physical condition resulting from defective genes or developmental deficiencies

Other hypernyms of subnormality include abnormality.

subnormality (noun)	abnormalcy (noun)
lack of normal development of intellectual capacities	an abnormal physical condition resulting from defective genes or developmental deficiencies
the state of being less than normal (especially with respect to intelligence)