Apsid

Part of speech: noun

Definitions

1. A curved architectural feature often found in churches or other structures, typically at the end of the nave
2. A semicircular recess that can be part of a building's design, often used in religious or classical architecture
3. An architectural term describing a circular or polygonal termination of a building or room, especially in ecclesiastical settings

Etymology: Ancient Greek "hapsis" meant "arch" or "vault," a curved structure, and came from "haptein," "to fasten," because an arch is built by fitting stones together. Latin borrowed the term, and it came to name the vaulted recess, usually at the east end of a church, that held the altar. Its half-dome roof is curved like the inside of a bowl, which explains the name. The same Greek root gave astronomers a separate sense. An orbit curves like an arch, so the points where a planet or satellite is nearest or farthest from the body it circles are called apsides. The church recess and the orbital point share a shape: both are curves.

Synonyms: apse, chancel, sanctuary, apse chapel