cornu vs complex body part

cornu and complex body part both are nouns.

Word	Noun	Adjective	Verb	Adverb
cornu	Yes	No	No	No
complex body part	Yes	No	No	No

As nouns, complex body part is a hypernym of cornu; that is, complex body part is a word with a broader meaning than cornu:

cornu: (anatomy) any structure that resembles a horn in shape
complex body part: a particular complex anatomical part of a living thing and its construction and arrangement

Other hypernyms of cornu include anatomical structure, bodily structure, body structure, structure.

cornu (noun)	complex body part (noun)
(anatomy) any structure that resembles a horn in shape	a particular complex anatomical part of a living thing and its construction and arrangement