The quality of something being round or curved in shape is its convexity. You could describe the convexity of a round, squat vase.

The noun convexity is somewhat technical for everyday use — you're more likely to see it in a math textbook than to hear a friend use it to talk about a goldfish bowl. Still, it is a perfectly good way to describe anything that curves or bulges outward, whether it's the belly of a Chinese Buddha or a balloon. Convexity comes from the adjective convex, with its Latin root word convexus, "vaulted or arched."

Definitions of convexity

n the property possessed by a convex shape

bulginess, roundedness
the property possessed by a rounded convexity
ellipticity, oblateness
the property possessed by a round shape that is flattened at the poles
Type of:
configuration, conformation, contour, form, shape
any spatial attributes (especially as defined by outline)

n a shape that curves or bulges outward

convex shape
show 20 types...
hide 20 types...
a slight rounded elevation where the malleus attaches to the eardrum
a slight convexity (as of the surface of a road)
a slight convexity in the shaft of a column; compensates for the illusion of concavity that viewers experience when the sides are perfectly straight
knob, node, thickening
any thickened enlargement
any long raised strip
peak, point, tip
a V shape
a convex shape that narrows toward a point
any solid convex shape that juts out from something
widow's peak
a V-shaped point in the hairline in the middle of the forehead
raphe, rhaphe
a ridge that forms a seam between two parts
small elevation on the grinding surface of a tooth
(military) the part of the line of battle that projects closest to the enemy
a sharp projection on an edge or surface
bulge, bump, excrescence, extrusion, gibbosity, gibbousness, hump, jut, prominence, protrusion, protuberance, swelling
something that bulges out or is protuberant or projects from its surroundings
a ridge on a corrugated surface
acantha, spine, spur
any sharply pointed projection
tail, tail end
any projection that resembles the tail of an animal
knife, tongue
any long thin projection that is transient
a projection or ridge that suggests a keel
the tip of an abscess (where the pus accumulates)
Type of:
a three-dimensional shape

Sign up, it's free!

Whether you're a student, an educator, or a lifelong learner, can put you on the path to systematic vocabulary improvement.