indentation vs concavity

indentation and concavity both are nouns.

Word	Noun	Adjective	Verb	Adverb
indentation	Yes	No	No	No
concavity	Yes	No	No	No

As nouns, concavity is a hypernym of indentation; that is, concavity is a word with a broader meaning than indentation:

Other hypernyms of indentation include concave shape, incurvation, incurvature.

indentation (noun)	concavity (noun)
the act of cutting into an edge with toothlike notches or angular incisions	the property possessed by a concave shape
the space left between the margin and the start of an indented line	a shape that curves or bends inward
the formation of small pits in a surface as a consequence of corrosion
a concave cut into a surface or edge (as in a coastline)