SINCE 1828

An Encyclopædia Britannica Company

the equator

Definition of the equator

:an imaginary circle around the middle of the Earth that is the same distance from the North Pole and the South Pole

The city of Quito, Ecuador, lies very close to the equator.

Word by Word Definitions

equator play

: the great circle of the celestial sphere whose plane is perpendicular to the axis of the earth
: 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
: a circle or circular band dividing the surface of a body into two usually equal and symmetrical parts

See the full definition of equator

Seen and Heard

What made you want to look up the equator? Please tell us where you read or heard it (including the quote, if possible).

show

WORD OF THE DAY

hew

play

to conform or adhere

Words at Play

alt-59e8c3440f453

I'll Have the Us(ual)

Shortening 'usual': easy to say, hard to spell

alt-59e77dc36c593

The Origins of 'Lobbyist'

From the front hallways to the back rooms

alt-59e673567065d

The History of the Word 'Terrorism'

Noah Webster first entered the term in 1840

alt-59e65152518a6

'Regimen' vs. 'Regiment'

The rule of thumb for words about rules

Ask the Editors

video-title-words-of-the-year-1066

Words of the Year: 1066

Or, Why Pig Meat is Called 'Pork' and Cow Meat is Called 'Beef'

How Often Is 'Biweekly'?

Don't get us started on 'bimonthly'

video-irregardless-grammar-peeve-blend-of-the-synonyms-irrespective-and-regardless

Irregardless

It is in fact a real word (but that doesn't mean you should use it).

video-moose-goose-weird-plurals

Weird Plurals

One goose, two geese. One moose, two... moose. What's up with that?

Word Games

one-green-toy-robot-amidst-many-red-toy-robots

The Exceptions Quiz III

Which of these things doesn't belong?

Take the quiz

knupfer-painting-solon-before-croesus

Forms of Government Quiz

Name that government! Or something like that.

Take the quiz

Name That Thing

Name That Thing

Test your visual vocabulary with our 10-question challenge!

Take the quiz

Syn City

Build a city of skyscrapers—one synonym at a time.

Play the game