Concavus

Part of speech: adjective

Definitions

1. A shape that is curved inward, resembling a bowl or a hollow structure
2. having a surface that dips inward, causing a depression or recess
3. characterizing a geometric form where the middle is lower than the edges, creating a cupped appearance

Etymology: The Latin "concavus" was built from "con-", an intensive prefix meaning "thoroughly" or "together," and "cavus," meaning "hollow." "Cavus" comes from the same root as "cave" and "cavity," so the word's core idea is simply a hollow space. Adding "con-" intensified that hollowness into a full, arched or rounded interior, the sense of something curving inward like a bowl. In Latin, "concavus" was used of anything hollowed out or arched over, such as the vault of the sky, which the Romans pictured as a great hollow dome. English took the word directly from Latin, and it has kept the same literal sense of a surface that curves inward, as opposed to "convex," which curves outward.

Synonyms: concave, curved inward, hollow, sunken, depressed

Antonyms: convex, bulging, raised, protruding, rounded