equa·​tor | \i-ˈkwā-tər, 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

At the equator, days and nights remain roughly 12 hours long. Valentina Pop, WSJ, "What Time Is It in Europe? Soon, the Answer Might Be Really Confusing," 18 Oct. 2018 Currently, Atlantic currents carry over half the heat energy in the ocean from the equator toward the North Pole. Scott K. Johnson, Ars Technica, "Mad scientists flip the Earth’s spin in climate models, watch water go nuts," 17 Oct. 2018 Most of the Jupiter’s heat is generated within the planet itself, NASA notes, and heats its equator more than the poles. Ashley May, USA TODAY, "Lightning on Jupiter: NASA finally discovers why it's there, and how bolts are similar to Earth's," 7 June 2018 The fundamentals of the technique are simple: As Jupiter whirls around its axis, the resulting force should raise a slight, perfectly symmetric bulge around the planet’s equator. Lee Billings, Scientific American, "Juno Peers Deep into Jupiter's Abyss to Reveal Weird Winds," 7 Mar. 2018 That’s when the sun appears to reach the Tropic of Cancer and then appears to retreat toward the equator. Blaine P. Friedlander Jr., Washington Post, "Skywatch: Saturn, Jupiter and Mars heading for opposition in June and July," 2 June 2018 Technically speaking, the equinox occurs when the sun is directly in line with the equator. Brian Resnick, Vox, "Summer is for meteor showers and stargazing. Here’s how to watch.," 22 June 2018 During that time, the North Hemisphere experiences the winter solstice, or the shortest day of the year, while those living south of the equator experience the longest day of the year. Madeline Farber, Fox News, "A guide to summer solstice, from Stonehenge to the earth's tilt," 21 June 2018 Nearer the equator, early elephants and antelope roamed Arabia’s grassy, wet interior, while North Africa was lushly forested where Saharan sand dunes drift today. Howard Lee, Ars Technica, "What happened last time it was as warm as it’s going to get later this century?," 18 June 2018

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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Statistics for equator

Last Updated

15 Nov 2018

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Time Traveler for equator

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

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More Definitions for equator


equa·​tor | \i-ˈkwā-tər \

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, ˈē-ˌ \

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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