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

The Great Red Spot, located on Jupiter about 22° south of its equator, is a gigantic anticyclonic storm with wind speeds up to 432 km/h (268 mph) and a size greater than Earth. —Kaif Shaikh, Interesting Engineering, 13 Nov. 2025

Meanwhile, Europa's shadow will be visible encroaching on the extreme left of Jupiter's disk at the outset of the double transit, slightly farther from the Jovian equator. —Anthony Wood, Space.com, 4 Nov. 2025

The region sat close to the planet’s equator, resulting in a greenhouse-like environment with high humidity and warm temperatures. —Irene Wright, Miami Herald, 31 Oct. 2025

About eighteen hours later, brilliant, blood-red auroras surged toward Earth’s equator. —Literary Hub, 27 Oct. 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