gibbosity vs caput

gibbosity and caput both are nouns.

Word	Noun	Adjective	Verb	Adverb
gibbosity	Yes	No	No	No
caput	Yes	No	No	No

As nouns, caput is a hyponym of gibbosity; that is, caput is a word with a more specific, narrower meaning than gibbosity:

gibbosity: something that bulges out or is protuberant or projects from its surroundings
caput: a headlike protuberance on an organ or structure

Other hyponyms of gibbosity include frontal eminence, occipital protuberance, belly, mogul, nub, nubble, snag, wart.

gibbosity (noun)	caput (noun)
something that bulges out or is protuberant or projects from its surroundings	the upper part of the human body or the front part of the body in animals; contains the face and brains
	a headlike protuberance on an organ or structure