convex

American  

[kon-veks, kuhn-, kon-veks] / kɒnˈvɛks, kən-, ˈkɒn vɛks /

adjective

1. having a surface that is curved or rounded outward.

2. Mathematics.

   1. (of a polygon) having all interior angles less than or equal to 180°.

   2. (of a set) having the property that for each pair of points in the set the line joining the points is wholly contained in the set.

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noun

1. a convex surface, part, or thing.

convex British  

/ ˈkɒnvɛks, kɒnˈvɛks /

adjective

1. curving or bulging outwards

2. physics having one or two surfaces curved or ground in the shape of a section of the exterior of a sphere, paraboloid, ellipsoid, etc

   a convex lens

3. maths (of a polygon) containing no interior angle greater than 180°

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verb

1. (tr) to make convex

convex Scientific  

/ kŏn′vĕks′ /

1. Curving outward, like the outer boundary of a circle or sphere.

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Other Word Forms

Derived Forms

• convexly
  adverb
• convexedness
  noun
• subconvex
  adjective
• convexedly
  adverb

Etymology

Origin of convex

1565–75; < Latin convexus equivalent to con- con- + -vexus, perhaps < *wek-sos, derivative of base of vehere to convey, if original sense was “brought together (to a single point)”

Explanation

If something is bulging outwards in a curve, it's convex in shape. The surfaces of soccer balls, old television screens, and eyeballs are all convex in shape. One of the most famous uses of a convex shape are the curving mirrors in a fun house. Not to be confused with its popular partner, the concave mirror, which curves inwards. How can you tell which is which? If you look like you're three feet tall and weigh 300 pounds, you're looking in a convex mirror. If you look like you're twelve feet tall weigh 30 pounds, you're looking in a concave mirror. Enjoy!

Example Sentences

But since contracts tied to the VIX expired on Wednesday morning, investors have been reupping their hedges, said Noel Smith, chief investment officer at Convex Asset Management.

From MarketWatch • Mar. 19, 2026

Canadian private-equity firm Onex is teaming up with American International Group to buy privately-held property and casualty insurer Convex for $7 billion.

From The Wall Street Journal • Oct. 30, 2025

It is part of a mission - the Convex Seascape Survey - which involves universities and research institutions around the globe working together to better understand how our ocean and climate are connected.

From BBC • Aug. 18, 2025

Convex mirrors diverge light rays and, thus, have a negative focal length.

From Textbooks • Aug. 12, 2015

This was a double Convex ground on both sides to one and the same Sphere, and its Focus was distant from it 83-2/5 Inches.

From Opticks or, a Treatise of the Reflections, Refractions, Inflections, and Colours of Light by Newton, Isaac, Sir