Definition of "celestial longitude" [celestial longitude]
The angular distance eastward from the vernal equinox along the ecliptic to the great circle drawn through the pole of the ecliptic and a celestial body.(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.