convex

UK/ˈkɒn.vɛks/US/ˈkɑn.vɛks/

adjectiveC1Rare in speech; mostly a word you read · #13,017 of 15,258mostly written

Convex means curving outward, like the back of a spoon. A convex lens, a convex mirror, the glass is slightly convex.

Its opposite is concave. A convex mirror is the wide-angle one at a blind junction or in a shop ceiling, because it shows a wider view at the cost of making everything look further away. A convex lens gathers light to a point and is what a magnifying glass and a long-sighted person's glasses use. Like concave, it also has a precise mathematical meaning about the shape of a curve or a set.

Definitions of convex

1adjectiveconvexCurving outward, like the outside of a ball.C1
“The convex mirror shows the whole junction.”
synonyms: bulging, domed

convex is a curved shape.

Where it comes from

Latin convexus meant arched or vaulted, and its origin beyond that is uncertain — possibly from vehere, to carry, by way of a vaulted roof carrying its own weight. Concave and convex arrived in English together as a pair and have never been used apart.

Latin
convexus — arched
Middle French
convexe
English, today
convex

Borrowed from Middle French convexe, from Latin convexus (“arched”).

Etymology from Wiktionary, CC BY-SA

Practised in Light & Shadow, Shapes & Lines

Practise this word

convex in the wild

In geometry, a set of points is convex if it contains every line segment between two points in the set.
Convex set
For example, a solid cube is a convex set, but anything that is hollow or has an indent, such as a crescent shape, is not convex.
Convex set
Many common families of convex polyhedra, with cubes and pyramids are familiar examples of such.
Polyhedron
In geometry, the convex hull, convex envelope or convex closure of a shape is the smallest convex set that contains it.
Convex hull
Convex hulls of open sets are open, and convex hulls of compact sets are compact.
Convex hull

1 / 2

From Wikipedia, CC BY-SA 4.0. These sentences were written by other people about their own subjects; they are here to show the word at work, not as anybody’s opinion.

← Vocabulary