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
  1. noun
    the property possessed by a convex shape
    synonyms: convexness
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    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)
  2. noun
    a shape that curves or bulges outward
    synonyms: convex shape
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    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
Word Family

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