from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A great circle on the celestial sphere in the same plane as the earth's equator. Also called equinoctial, equinoctial circle.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A great circle on the celestial sphere, coincident with the plane of earth's equator.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the great circle on the celestial sphere midway between the celestial poles
Sorry, no etymologies found.