equa·​tor | \ i-ˈkwā-tər How to pronounce equator (audio) , ˈē-ˌkwā- \

Definition of equator

1 : the great circle of the celestial sphere whose plane is perpendicular to the axis of the earth
2 : a great circle of the earth or a celestial body that is everywhere equally distant from the two poles and divides the surface into the northern and southern hemispheres
3a : a circle or circular band dividing the surface of a body into two usually equal and symmetrical parts
b : equatorial plane the equator of a dividing cell

Examples of equator in a Sentence

Recent Examples on the Web The clouds also moved from the equator toward either of the planet’s poles, distributing the momentum needed for fast super-rotation. Theresa Machemer, Smithsonian Magazine, "The Forces Behind Venus’ Super-Rotating Atmosphere," 28 Apr. 2020 Earth’s magnetic field lines plunge into the ground at angles that increase from the equator to the poles. Paul Voosen, Science | AAAS, "Diamond microscope reveals slow crawl of Earth’s ancient crust," 22 Apr. 2020 This occurs thanks to the sun's rays hitting the Earth directly at the equator since the Earth's rotation axis—which is tilted at a 23.5 degree angle—is perpendicular to the sun. Daisy Hernandez, Popular Mechanics, "What Is the Spring Equinox?," 19 Mar. 2020 At the equator InSight landed at a region of Mars called Elysium Planiti, a region sandwiched between the southern highlands and the second largest volcano on the planet, Elysium. John Timmer, Ars Technica, "Marsquakes and ancient magnetic fields: InSight’s first data," 25 Feb. 2020 Scientists have used data from the first eight flybys to determine the amount of water in Jupiter's atmosphere at the equator, according to a new study. Ashley Strickland, CNN, "How much water does Jupiter really have? Here's what NASA's Juno mission found," 19 Feb. 2020 Ryugu has a somewhat angular shape and is a little less than a kilometer across, and its equator bulges out in a distinctive ridge that makes the asteroid resemble a spinning top. Scott K. Johnson, Ars Technica, "Incredible video shows Hayabusa2 pogo-bouncing off asteroid," 7 May 2020 Models suggest that when the basin formed, Pluto’s equator was elsewhere, but that after the impact occurred, an underground watery ocean began upwelling into the chasm while ice gathered atop it. Robin George Andrews, Scientific American, "Collision on One Side of Pluto Ripped Up Terrain on the Other, Study Suggests," 26 Mar. 2020 Over time, the orbiter will leverage further encounters with Venus to tip its own orbit out of the plane that Earth and the other planets inhabit around the Sun’s equator. Charlie Wood, Popular Science, "This new solar orbiter will peek at some of the sun’s most secretive spots," 28 Jan. 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'equator.' 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 equator

14th century, in the meaning defined at sense 1

History and Etymology for equator

Middle English, from Medieval Latin aequator, literally, equalizer, from Latin aequare

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Time Traveler for equator

Time Traveler

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

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Statistics for equator

Last Updated

30 May 2020

Cite this Entry

“Equator.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/equator. Accessed 6 Jun. 2020.

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More Definitions for equator


equa·​tor | \ i-ˈkwā-tər How to pronounce equator (audio) \

Kids Definition of equator

: an imaginary circle around the earth everywhere equally distant from the north pole and the south pole


equa·​tor | \ i-ˈkwāt-ər How to pronounce equator (audio) , ˈē-ˌ How to pronounce equator (audio) \

Medical Definition of equator

1 : a circle or circular band dividing the surface of a body into two usually equal and symmetrical parts especially at the place of greatest width the equator of the lens of the eye

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