hemisphere

American  

[hem-i-sfeer] / ˈhɛm ɪˌsfɪər /

noun

hemispheres plural

1. (often initial capital letter) half of the terrestrial globe or celestial sphere, especially one of the halves into which the earth is divided.

2. a map or projection representing one of these halves.

3. a half of a sphere.

4. Anatomy. either of the lateral halves of the cerebrum or cerebellum.

5. the area within which something occurs or dominates; sphere; realm.

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hemisphere British  

/ ˌhɛmɪˈsfɛrɪk, ˈhɛmɪˌsfɪə /

noun

1. one half of a sphere

2. 1. half of the terrestrial globe, divided into northern and southern hemispheres by the equator or into eastern and western hemispheres by some meridians, usually 0° and 180°

   2. a map or projection of one of the hemispheres

3. either of the two halves of the celestial sphere that lie north or south of the celestial equator

4. anatomy short for cerebral hemisphere

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hemisphere Scientific  

/ hĕm′ĭ-sfîr′ /

1. One half of a sphere, formed by a plane that passes through the center of the sphere.

2. Either the northern or southern half of the Earth as divided by the equator, or the eastern or western half as divided by a meridian, especially the prime meridian.

3. One half of the celestial sphere as divided by any of various great circles, especially the celestial equator and the ecliptic.

4. See more at celestial sphere

5. See cerebral hemisphere

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hemisphere Cultural  

1. Any half of the Earth's surface.

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Other Word Forms

Derived Forms

• hemispheric
  adjective

Inflected Forms

Nouns

• hemispheres
  plural

Etymology

Origin of hemisphere

1325–75; < Latin hēmisphaerium < Greek hēmisphaírion; replacing Middle English emysperie < Old French emispere < Latin

Explanation

A hemisphere is half of a sphere. If it’s a cold winter in the northern hemisphere, take a winter getaway to sunbathe somewhere in the southern hemisphere. Hemisphere comes from the Greek, and combines the prefix hemi-, for "half," with sphere, or "perfectly round ball." We talk about the earth as divided at the equator into the northern and southern hemispheres (or divided at the prime meridian into eastern and western hemispheres). In biology, there are two cerebral, or brain, hemispheres — also known as the right and left sides of the brain.

Example Sentences

In the northern hemisphere, June's full Moon is different from others in the calendar year as it is the lowest-hanging in the sky.

From BBC • Jun. 28, 2026

They point out that, while Australia and New Zealand’s geography justify a scaled ultra long-haul fleet, Qantas’s northern hemisphere peers don’t appear to have sufficient use cases to warrant the investment.

From The Wall Street Journal • Jun. 23, 2026

“I think that some of the hemisphere is willing to play along with it because the hemisphere has issues, including security issues, where the U.S. can be of assistance,” Bosworth said.

From Los Angeles Times • Jun. 21, 2026

"They tend to be in the northern hemisphere, particularly so, parts of Scandinavia."

From Barron's • Jun. 16, 2026

The left hemisphere and the right hemisphere are separated on top by a deep crack—the interhemispheric fissure—but joined in the middle of the brain by a thick mat of nerves—the corpus callosum.

From "Phineas Gage" by John Fleischman

Related Words

• fraction