Clerestory

Part of speech: noun

Pronunciation: /ˈklɪəɹ.stɔːɹi/

Definitions

1. an upper tier of windows in a church or large building allowing light to enter above the roof of adjoining structures
2. a row of windows positioned high on interior walls to illuminate the central portion of a building from above
3. elevated windows set in the upper walls of a structure to provide natural illumination to the main interior space

Etymology: The clerestory is a compound built from two plain English words, and its surprise lies in how literally it names the thing. "Clere" was the Middle English form of "clear," meaning light or lighted, while "story" meant a level or floor of a building, the same sense that survives in "storey." Put together, the name describes a whole level of a building whose job is to let in light: the upper band of windows that rises above the lower roofs of aisles or neighbouring rooms. That physical logic explains why the term fits so well. In a large church, the nave walls rose high enough that the upper storey could be pierced with windows, flooding the central space with daylight that the lower aisles could not provide. Builders were not naming a decorative feature so much as a storey defined by its clear light.

Synonyms: lightwell, skylight, window, transom, lancet