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

Dinosaurs have become mundane to the viewing public, and due to climate change, can only survive near the Earth’s equator, where travel is expressly forbidden. —Katie Walsh, Twin Cities, 5 July 2025

Understanding The Tropic Of Cancer The Tropic of Cancer is a line 23.4 degrees north of the Earth's equator through The Bahamas, Mexico, Egypt, Libya, Niger, Algeria, Mauritania, Mali, Chad, Saudi Arabia, United Arab Emirates, Oman, India, Myanmar, China and Taiwan. —Jamie Carter, Forbes.com, 20 June 2025

On March 20, the sun will shine directly over Earth's equator, creating roughly 12 hours of day and night across the world. —John Tufts, IndyStar, 20 Feb. 2025

All pre-existing images of the sun were taken from within about 7 degrees of its equator. —Margherita Bassi, Smithsonian Magazine, 12 June 2025

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