Concavity

Part of speech: noun

Pronunciation: /kəŋˈkævɪti/

Definitions

1. A surface or shape that curves inward like the interior of a bowl or sphere
2. A geometric feature that indicates a surface bent inward, resembling a bowl's inner curve or a dip in its form
3. The quality of a shape that bends inward, creating a hollow or recessed area like the inside of a cup

Etymology: Concavity comes from the Latin adjective "concavus," meaning hollow or arched, built from "con-" (an intensive prefix, here meaning thoroughly) and "cavus," hollow. "Cavus" is also the source of English "cave" and "cavity," so the word shares its core with several words for hollow spaces. The adjective "concave" came into English first, and "concavity" was formed from it by adding the suffix "-ity," which turns an adjective into a noun naming a quality. The noun reached English by way of Old French "concavité," which took the same Latin base and suffix. Because the English noun was built from the adjective already in use, its meaning stayed close to the physical sense: a hollowed or inward-curving surface, the kind found inside a bowl or a sphere. Its sense has remained largely literal across its history.

Synonyms: curvature, depression

Antonyms: convexity