from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Architecture A half-circle window, often with sash bars arranged like the ribs of a fan.
- n. Chiefly British A transom.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. a semicircular or semioval window over a door or other window, normally having a fan-like structure of ribs; sometimes hinged to the transom
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a window in a roof to admit daylight
- n. a window above a door that is usually hinged to a horizontal crosspiece over the door
- n. a semicircular window over a door or window; usually has sash bars like the ribs of a fan
From fan + light ("window") (Wiktionary)