Definition of "celestial equator" [celestial equator]

• A great circle on the celestial sphere in the same plane as the earth's equator. Also called equinoctial, equinoctial circle. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.