Definition of "ecliptic" [e•clip•tic]

• The intersection plane of the earth's orbit with the celestial sphere, along which the sun appears to move as viewed from the earth. (noun)
• A great circle inscribed on a terrestrial globe inclined at an approximate angle of 23°27ʹ to the equator and representing the apparent motion of the sun in relation to the earth during a year. (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.

• "The Oort cloud would have its inner disk at the ecliptic from the Kuiper belt."
• "An answer to some of your questions: the plane-of-the-ecliptic is a geometric term that basically means the natural horizon of space, versus an an artificial horizon."
• "The plane of the ecliptic is well seen in this picture from the 1994 lunar prospecting Clementine spacecraft."