retroflexion vs abnormalcy

retroflexion and abnormalcy both are nouns.

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

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

retroflexion: a turning or tilting backward of an organ or body part
abnormalcy: an abnormal physical condition resulting from defective genes or developmental deficiencies

Other hypernyms of retroflexion include abnormality.

retroflexion (noun)	abnormalcy (noun)
the act of bending backward	an abnormal physical condition resulting from defective genes or developmental deficiencies
an articulatory gesture made by turning the tip of the tongue back against the roof of the mouth
a turning or tilting backward of an organ or body part