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

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

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

These are examples of what Block describes as convex trades, which have a non-linear, upward payoff profile but have limited downside exposure to adverse moves.

From MarketWatch • Apr. 1, 2026

The bottle has an unusual convex base, meaning it cannot stand upright, and it is made of coarse glass, full of tiny air bubbles.

From BBC • Nov. 8, 2024

On a convex or tubular structure such as the outside surface of a blood vessel, cells tend to move circumferentially around the shape.

From Science Daily • Mar. 18, 2024

The most aggressively three-dimensional entries are by Graham Caldwell, who mounts multiple glass objects, such as transparent orbs or convex mirrors, on black metal armatures that jut from the wall.

From Washington Post • Feb. 24, 2023

Behind my half-head, in the center of the picture, in the empty sky, a pier glass is hanging, convex and encircled by an ornate frame.

From "Cat's Eye" by Margaret Atwood