convex shape vs entasis

convex shape and entasis both are nouns.

Word	Noun	Adjective	Verb	Adverb
convex shape	Yes	No	No	No
entasis	Yes	No	No	No

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

convex shape: 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 convex shape include umbo, camber, knob, node, thickening, ridge, peak, point, tip, taper, projection.

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