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

Related Words

• ring
• sphere