equator

[ ih-kwey-ter ]

noun

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.

equator

/ 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

equator

/ 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.

equator

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

Word History and Origins

Origin of equator¹

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

Word History and Origins

Origin of equator¹

C14: from Medieval Latin ( circulus ) aequātor ( diei et noctis ) (circle) that equalizes (the day and night), from Latin aequāre to make equal

Example Sentences

The measurements suggest that the asteroid’s rubble pile is unevenly distributed along its surface and is especially light at the asteroid’s equator.

From MIT Technology Review

It’s not perfectly round, but larger and cooler at its equator than at the poles, making the poles of the star appear brighter.

From Popular-Science

Scientists usually forecast flu seasons’ severity in the north by watching what happens south of the equator, where flu season falls in the middle of the year.

From Science News

All of the familiar ones orbit in a single plane aligned with the Sun's equator and move in the same direction.

From Ars Technica

They run parallel to the ground and point toward the equator.

From Science News For Students

Yasuni Natonal Park, where the equator meets the Andes, is famed for its fabulous variety of plants and animals.

From The Daily Beast

An orbit near the equator was important for a variety of reasons.

From The Daily Beast

Those storms kicked up in the collision zone around the equator spin westward off the coast of Cape Verde.

From The Daily Beast

And yet the trees are cultivated in every country within 15 degrees of the Equator, so a virtual cocoa belt encircles the globe.

From The Daily Beast

It is about three leagues wide and is forty-four and one half degrees from the Equator.

From Project Gutenberg

The difference in the length of day and night decreases more and more the nearer you approach the Equator.

From Project Gutenberg

It was of a cylindrical shape, having a deep zone at the equator, and a containing capacity of about 300 feet.

From Project Gutenberg

This covering extends rather less far toward the planet's equator than does the snow sheet on our continents.

From Project Gutenberg

Then let us imagine the particle moving toward the equator with the speed of an ordinary wind.

From Project Gutenberg

Related Words

• ring
• sphere