infantilism vs abnormalcy

infantilism and abnormalcy both are nouns.

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

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

infantilism: an abnormal condition in which an older child or adult retains infantile characteristics
abnormalcy: an abnormal physical condition resulting from defective genes or developmental deficiencies

Other hypernyms of infantilism include abnormality.

infantilism (noun)	abnormalcy (noun)
infantile behavior in mature persons	an abnormal physical condition resulting from defective genes or developmental deficiencies
an abnormal condition in which an older child or adult retains infantile characteristics