Concave or convex?
concave is an adjective meaning “Curved like the inner surface of a sphere or bowl”; convex is an adjective meaning “Curved or bowed outward like the outside of a bowl, circle, or sphere”. In written English (wordfreq, 2021 data) convex is about 1.7 times as common as concave.
What is the difference between concave and convex?
| concave | convex | |
|---|---|---|
| Part of speech | adjective, noun, verb | adjective, noun, verb |
| Meaning | Curved like the inner surface of a sphere or bowl Not convex; having at least one internal angle greater than 180 degrees A concave surface or curve | Curved or bowed outward like the outside of a bowl, circle, or sphere having an epigraph that is a convex set Any convex body or surface |
| Example | Aristotle makes [Fire] to move to the concave of the Moon. - Thomas Salusbury (1661) | none recorded |
| Pronunciation | /ˈkɒn.keɪv/ /kɒnˈkeɪv/ /ˈkɑn.keɪv/ | /ˈkɒn.vɛks/ /kɒnˈvɛks/ /kənˈvɛks/ |
| In writing | 1.0 times per million words | 1.8 times per million words |
Sources: concave and convex in the English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0); written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
Every current meaning of concave and convex
concave
- 1
Curved like the inner surface of a sphere or bowl
- 2
A concave surface or curve
- 3
To render concave, or increase the degree of concavity
- 4
Not convex; having at least one internal angle greater than 180 degrees
- 5
The vault of the sky
- 6
Satisfying the property that all segments connecting two points on the function's graph lie below the function
- 7
One of the celestial spheres of the Ptolemaic or geocentric model of the world
Aristotle makes [Fire] to move to the concave of the Moon. - Thomas Salusbury (1661)
- 8
Hollow; empty
convex
- 1
Curved or bowed outward like the outside of a bowl, circle, or sphere
- 2
Any convex body or surface
- 3
To form a convex curve or surface; to become convex
- 4
having an epigraph that is a convex set
- 5
A playing card made convex for use in cheating
- 6
To cause to form a convex curve or surface; to make convex
- 7
having no internal angles greater than 180 degrees
- 8
A small convex mirror used to cheat by observing other players' cards
Source: the English Wiktionary, dump of September 2, 2026 (CC BY-SA 4.0); obsolete, archaic, dialect and rare senses left out.
Which is more common, concave or convex?
concave appears 1.0 times per million words; convex 1.8 times per million words.
concave 1.0 times per million wordsconvex 1.8 times per million words
Source: written frequency: wordfreq 3.1 (a 2021 snapshot of Wikipedia, subtitles, news, books, web text and social media).
How many people search concave vs convex?
“concave vs convex” is searched about 27,100 times a month on Google and 2,470 on Bing in the United States. Google counts close variants of a query together (“convex vs concave”, “concave or convex”).
Sources: Google Ads keyword data through DataForSEO and Microsoft Advertising keyword data through DataForSEO, the average month from September 2025 to August 2026.