amastia vs abnormalcy

amastia and abnormalcy both are nouns.

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

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

amastia: absence of the mammary glands (either through surgery or developmental defect)
abnormalcy: an abnormal physical condition resulting from defective genes or developmental deficiencies

Other hypernyms of amastia include abnormality.

amastia (noun)	abnormalcy (noun)
absence of the mammary glands (either through surgery or developmental defect)	an abnormal physical condition resulting from defective genes or developmental deficiencies