pigeon breast vs misshapenness

pigeon breast and misshapenness both are nouns.

Word	Noun	Adjective	Verb	Adverb
pigeon breast	Yes	No	No	No
misshapenness	Yes	No	No	No

As nouns, misshapenness is a hypernym of pigeon breast; that is, misshapenness is a word with a broader meaning than pigeon breast:

pigeon breast: abnormal protrusion of the breastbone caused by rickets
misshapenness: an affliction in which some part of the body is misshapen or malformed

Other hypernyms of pigeon breast include deformity, malformation.

pigeon breast (noun)	misshapenness (noun)
abnormal protrusion of the breastbone caused by rickets	an affliction in which some part of the body is misshapen or malformed