convexity vs entasis

convexity and entasis both are nouns.

Word	Noun	Adjective	Verb	Adverb
convexity	Yes	No	No	No
entasis	Yes	No	No	No

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

convexity: a shape that curves or bulges outward
entasis: a slight convexity in the shaft of a column; compensates for the illusion of concavity that viewers experience when the sides are perfectly straight

Other hyponyms of convexity include umbo, camber, knob, node, thickening, ridge, peak, point, tip, taper, projection.

convexity (noun)	entasis (noun)
the property possessed by a convex shape	a slight convexity in the shaft of a column; compensates for the illusion of concavity that viewers experience when the sides are perfectly straight
a shape that curves or bulges outward