Convex

How to spell convex

6 letters · 2 syllables

How to pronounce convex

Say the part in capitals loudest.

What does convex mean?

1. adjectiveHaving a surface or boundary that curves outward, like the exterior of a sphere or a magnifying lens.

Convex in a sentence

• The magnifying glass uses a convex lens to enlarge the print.

• The security mirror at the shop entrance is convex so it shows a wide view.

Where does convex come from?

Language of origin: Latin

This word comes from the Latin convexus, an adjective meaning 'vaulted, arched, or rounded', the kind of curve you see on the outside of a dome. It was built from the prefix con-, meaning 'together', joined to a root linked to the verb vehere, 'to carry' or 'to bring', so the original image was of surfaces drawn together into a rounded vault. Latin writers used convexus for the curving sky as well as for any bulging surface. English took the word in the middle of the sixteenth century, partly through French, as a precise term for geometry and optics, where it stands as the exact opposite of 'concave'. The spelling trap is small but real: it ends in the unusual letter sequence -vex, and writers sometimes pause over the single x, which here simply preserves the Latin form.

How the word is built

• con- (together)
• vex (from Latin convexus: vaulted, arched, curved outward)