equator

American  

[ih-kwey-ter] / ɪˈkweɪ tər /

noun

• equators
  plural

1. the great circle on a sphere or heavenly body whose plane is perpendicular to the axis, equidistant everywhere from the two poles of the sphere or heavenly body.

2. the great circle of the earth that is equidistant from the North Pole and South Pole.

3. a circle separating a surface into two congruent parts.

4. celestial equator.

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equator British  

/ ɪˈkweɪtə /

noun

1. the great circle of the earth with a latitude of 0°, lying equidistant from the poles; dividing the N and S hemispheres

2. a circle dividing a sphere or other surface into two equal symmetrical parts

3. See magnetic equator

4. astronomy See celestial equator

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equator Scientific  

/ ĭ-kwā′tər /

1. An imaginary line forming a great circle around the Earth's surface, equidistant from the poles and in a plane perpendicular to the Earth's axis of rotation. It divides the Earth into the Northern and Southern hemispheres and is the basis from which latitude is measured.

2. A similar circle on the surface of any celestial body.

3. The celestial equator.

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equator Cultural  

1. An imaginary circle around the Earth, equidistant from the North Pole and South Pole.

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Other Word Forms

Noun Inflected Forms

• equators
  plural

Etymology

Origin of equator

1350–1400; Middle English < Medieval Latin aequātor, Latin: equalizer (of day and night, as when the sun crosses the equator). See equate, -tor

Explanation

An equator is a circle that divides the surface of an object into two equal halves. If you're freezing up there in Iceland, get yourself on down closer to the earth's equator, where it's nice and warm. An equator is an invisible line that divides a globe into two parts, north and south. To remember equator, recall the root "equa" from the Latin word aequus, meaning "equal." An equator makes things "equal." If you drew a line that divided a globe into two parts that were not equal, the line couldn't be called an equator. If you live at the North Pole and you're buddy lives at the South, meet halfway, somewhere along the equator—perhaps in Brazil, for Carnaval.

Example Sentences

See Examples For:

equator equators

Temperature variations and anomalies in countries close to the equator are typically smaller than in temperate climates.

From Barron's ● Aug. 10, 2026

As cooler, drier air spreads into the central Pacific, evaporation decreases, atmospheric circulation weakens, and winds along the equator strengthen.

From Science Daily ● Jul. 3, 2026

Bee species living closer to the equator appeared more vulnerable to climate change, with tropical bees facing the highest overall risk.

From Science Daily ● Jun. 18, 2026

A dusk/dawn SSO orbit follows the earth’s rotation, passing near the poles, crossing the equator about the same time each day.

From The Wall Street Journal ● May 12, 2026

I slid down Russia and dropped off the equator.

From "The Titan's Curse" by Rick Riordan

Unlike hot Jupiters, which can orbit their stars at almost any tilt, warm Jupiters are almost always aligned with their stars' equators.

From Science Daily ● Oct. 15, 2025

He said it's mathematically feasible that these waves could also be the reason warm Jupiters align so closely with their host stars' equators.

From Science Daily ● Oct. 15, 2025

Standard formation theories posit that when planets are born, their equators are pointed toward the star and their poles point straight out of the disk that surrounds them.

From Scientific American ● Mar. 4, 2019

And science has finally come up with an explanation for what comes naturally to most home cooks: Eggs crack best around their equators, says MIT mechanical engineer Pedro Reis, because of their geometry.

From Slate ● Sep. 26, 2012

Together they shared the secret language of pericynthion altitudes and orbital planes and lunar equators.

From "Hidden Figures" by Margot Lee Shetterly

Related Words

• ring
• sphere