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ecliptic

[ih-klip-tik]
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noun
  1. Astronomy.
    1. the great circle formed by the intersection of the plane of the earth's orbit with the celestial sphere; the apparent annual path of the sun in the heavens.
    2. an analogous great circle on a terrestrial globe.
  2. Astrology. the great circle of the ecliptic, along which are located the 12 houses and signs of the zodiac.
adjective Also e·clip·ti·cal.
  1. pertaining to an eclipse.
  2. pertaining to the ecliptic.

Origin of ecliptic

1350–1400; Middle English < Medieval Latin eclīptica, feminine of eclīpticus < Greek ekleiptikós, equivalent to ekleíp(ein) (see eclipse) + -tikos -tic
Related formse·clip·ti·cal·ly, adverbnon·e·clip·tic, adjectivenon·e·clip·ti·cal, adjectivenon·e·clip·ti·cal·ly, adverbun·e·clip·tic, adjectiveun·e·clip·ti·cal, adjectiveun·e·clip·ti·cal·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for ecliptic

Historical Examples

  • There is no distinction between the equator and the ecliptic.

    The Republic

    Plato

  • The centre of the circle in the constellation of Draco is the pole of the ecliptic.

    The Story of the Heavens

    Robert Stawell Ball

  • We shall, for simplicity, refer only to a star at the pole of the ecliptic.

    The Story of the Heavens

    Robert Stawell Ball

  • This region lies in the constellation Draco, at the pole of the ecliptic.

    The Story of the Heavens

    Robert Stawell Ball

  • That part of the ecliptic whence the sun descends southward.

    The Sailor's Word-Book

    William Henry Smyth


British Dictionary definitions for ecliptic

ecliptic

noun
  1. astronomy
    1. the great circle on the celestial sphere representing the apparent annual path of the sun relative to the stars. It is inclined at 23.45° to the celestial equator. The poles of the ecliptic lie on the celestial sphere due north and south of the plane of the ecliptic
    2. (as modifier)the ecliptic plane
  2. an equivalent great circle, opposite points of which pass through the Tropics of Cancer and Capricorn, on the terrestrial globe
adjective
  1. of or relating to an eclipse
Derived Formsecliptically, adverb
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for ecliptic

n.

late 14c., "the circle in the sky followed by the Sun," from Medieval Latin ecliptica, from Late Latin (linea) ecliptica, from Greek ekliptikos "of an eclipse" (see eclipse (n.)). So called because eclipses happen only when the Moon is near the line. Related: Ecliptical.

Online Etymology Dictionary, © 2010 Douglas Harper

ecliptic in Science

ecliptic

[ĭ-klĭptĭk]
  1. The great circle on the celestial sphere that represents the Sun's apparent path among the background stars in one year. The northernmost point this path reaches on the celestial sphere is the Tropic of Cancer, its southernmost point is the Tropic of Capricorn, and it crosses the celestial equator at the points of vernal and autumnal equinox.♦ The plane of the ecliptic is the imaginary plane that intersects the celestial sphere along the ecliptic, and the north and south ecliptic poles are the points where a perpendicular line through the middle of this plane intersect the sphere. The plane of the ecliptic corresponds to the plane in which the Earth orbits the Sun. If the Earth's axis were not tilted, the ecliptic would be identical to the celestial equator and the ecliptic poles identical to the celestial poles. In this case, the Sun's path would not move northward or southward from the equator during the year. As it is, the plane of the celestial equator is tilted 23.45° to the plane of the ecliptic, corresponding to the tilt of the Earth's axis with respect to its orbital plane, giving the Sun its apparent northward and southward movement among the background stars. See illustration at celestial sphere.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.