equator

noun

equa·​tor i-ˈkwā-tər 

ˈē-ˌkwā-

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

3

a

: 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

4

: great circle

Examples of equator in a Sentence

Recent Examples on the Web

Because the ice giant takes just over 84 Earth years to complete one orbit around the sun, the researchers mainly got to observe the planet's northern spring as the sun moved from shining directly over the planet's equator to almost directly over its north pole by 2030. —Sharmila Kuthunur, Space.com, 1 Apr. 2025

The robotic explorer is operating near the moon’s equator after a successful touchdown on March 2. —Jackie Wattles, CNN, 7 Mar. 2025

While Apollo landed near the moon’s equator, Chandrayaan touched down at a latitude of 69 degrees north—well into the moon’s previously unexplored polar regions. —Tom Hawking, Popular Science, 6 Mar. 2025

Measuring ring-material detected by Cassini falling into Saturn’s equator allowed astronomers to give the rings another 100 million years to live. —Eric Lagatta, USA TODAY, 30 Nov. 2024

Word History

Etymology

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

First Known Use

14th century, in the meaning defined at sense 1

Phrases Containing equator

• celestial equator
• magnetic equator
• the equator

Rhymes for equator

• coater
• creator
• curator
• debater
• deflator
• dictator
• dilator
• locator
• mutator
• piscator
• pronator
• relator

Kids Definition

equator

noun

equa·​tor i-ˈkwāt-ər 

ˈē-ˌkwāt-

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

Medical Definition

equator

noun

equa·​tor i-ˈkwāt-ər  ˈē-ˌ 

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

2

: equatorial plane