fossa vs incurvature

fossa and incurvature both are nouns.

Word	Noun	Adjective	Verb	Adverb
fossa	Yes	No	No	No
incurvature	Yes	No	No	No

As nouns, incurvature is a hypernym of fossa; that is, incurvature is a word with a broader meaning than fossa:

Other hypernyms of fossa include bodily cavity, cavity, cavum, concave shape, concavity, incurvation.

fossa (noun)	incurvature (noun)
largest carnivore of Madagascar; intermediate in some respects between cats and civets	a shape that curves or bends inward
a concavity in a surface (especially an anatomical depression)