eclip·​tic | \ i-ˈklip-tik How to pronounce ecliptic (audio) \

Definition of ecliptic

 (Entry 1 of 2)

: of or relating to the ecliptic or an eclipse



Definition of ecliptic (Entry 2 of 2)

: the great circle of the celestial sphere that is the apparent path of the sun among the stars or of the earth as seen from the sun : the plane of the earth's orbit extended to meet the celestial sphere

Examples of ecliptic in a Sentence

Recent Examples on the Web: Adjective The mission will search for exoplanets in the ecliptic, which is the plane of Earth's orbit around the sun. Ashley Strickland, CNN, 24 Oct. 2020 Fomalhaut lies way south of the ecliptic, which, on sky charts, depicts the sun’s annual path in front of the constellations of the zodiac. Paul Douglas, Star Tribune, 27 Sep. 2020 Instead of orbiting the star along the ecliptic, or the plane parallel to its equator, Solar Orbiter will have a highly inclined orbit that will give us a first glimpse of the solar poles. Nola Taylor Redd, Smithsonian Magazine, 28 Aug. 2020 During that second year, the probe will also observe areas around the ecliptic, the plane of Earth's orbit around the sun. Mike Wall, Scientific American, 12 Aug. 2020 When the sun formed it was already accompanied by a swirl of gas and dust orbiting in that ecliptic plane that the planets and most asteroids would eventually occupy. Dennis Overbye, New York Times, 28 Apr. 2020 The first good look at the sun's poles won't come until 2025, when Solar Orbiter will reach a trajectory of 17 degrees above the ecliptic plane — where the Earth and the rest of the planets orbit. Amy Thompson, Scientific American, 10 Feb. 2020 Instead the moon’s orbit is inclined to the ecliptic plane by about five degrees. Simon J. Lock, Scientific American, 2 July 2019 And Mercury’s orbit intersects with the ecliptic twice during each revolution around the sun, currently in early May and November. Brigit Katz, Smithsonian, 7 Nov. 2019 Recent Examples on the Web: Noun The ecliptic is the plane of the solar system on which all the planets orbit the sun, and the moon travels nearby. Kristen Rogers, CNN, 27 Feb. 2020 Until now, almost all of the solar-watching spacecraft have orbited in the ecliptic, or the same plane that the planets travel around the sun. Kenneth Chang, New York Times, 10 Feb. 2020 The planets and the moon follow roughly the same path through the sky, which is called the ecliptic. Kristen Rogers, CNN, 27 Feb. 2020 By the modern definition, New Moon occurs when the Moon and Sun are at the same geocentric ecliptic longitude. Fox News, 21 Feb. 2020 This craft will spend the next two years performing fly-bys of Venus and Earth, using the gravity of both planets to kick itself into an unusual orbit that will take it well above the ecliptic, the plane in which all of the sun’s planets orbit. The Economist, 13 Feb. 2020 Mercury’s orbit is inclined seven degrees to the ecliptic, or plane of Earth’s orbit, as Bob King of Sky and Telescope explains. Brigit Katz, Smithsonian, 7 Nov. 2019 The moon would have formed in the plane of Earth’s equator, with its orbit also tilted far from the ecliptic. Simon J. Lock, Scientific American, 2 July 2019 In this case, Pluto is passing from above the ecliptic to below it, which makes this specific point Pluto’s descending node. Avery Thompson, Popular Mechanics, 13 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ecliptic.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of ecliptic


14th century, in the meaning defined above


15th century, in the meaning defined above

History and Etymology for ecliptic


Middle English ekliptik, borrowed from Latin eclīpticus, borrowed from Greek ekleiptikós, from ekleípein "to be obscured (of a celestial body)" + -t-, verbal adjective ending + -ikos -ic entry 1 — more at eclipse entry 1


Middle English ekliptik, borrowed from Medieval Latin eclīptica (short for eclīptica līnea "ecliptic line"), from feminine of Latin eclīpticus ecliptic entry 1; so called because eclipses occur on or near the ecliptic

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Time Traveler for ecliptic

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The first known use of ecliptic was in the 14th century

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Cite this Entry

“Ecliptic.” Dictionary, Merriam-Webster, Accessed 12 Jun. 2021.

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More from Merriam-Webster on ecliptic

Britannica English: Translation of ecliptic for Arabic Speakers Encyclopedia article about ecliptic


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