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• Western Hemisphere
  Western Hemisphere

  noun

  the western part of the terrestrial globe, roughly extending from the prime meridian west to the antimeridian: sometimes considered synonymous with the New World because the Americas are its primary composition, the Western Hemisphere technically extends into western Eurasia and Africa, easternmost Siberia, and part of Antarctica as well.
• western hemisphere
  western hemisphere

  noun

  that half of the globe containing the Americas, lying to the west of the Greenwich or another meridian

Western Hemisphere

American  

[wes-tern hem-i-sfeer] / ˈwɛs tərn ˈhɛm ɪˌsfɪər /

noun

1. the western part of the terrestrial globe, roughly extending from the prime meridian west to the antimeridian: sometimes considered synonymous with the New World because the Americas are its primary composition, the Western Hemisphere technically extends into western Eurasia and Africa, easternmost Siberia, and part of Antarctica as well.

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western hemisphere British  

noun

1. that half of the globe containing the Americas, lying to the west of the Greenwich or another meridian

2. the lands contained in this, esp the Americas

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Western Hemisphere Scientific  

/ wĕs′tərn /

1. The half of the Earth that includes North America, Central America, and South America, as divided roughly by the 0° and 180° meridians.

2. See more at prime meridian

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Etymology

Origin of Western Hemisphere

First recorded in 1640–50

Example Sentences

Western Hemisphere hantavirus strains are so deadly because they can attack the lungs and make them leak.

From Los Angeles Times • May 14, 2026

MP is the largest miner of rare-earth materials in the Western Hemisphere and is involved in the entire chain, including the making of rare-earth magnets.

From Barron's • May 7, 2026

This all comes as the US has also explicitly shifted its focus away from Europe and towards what it calls the "Western Hemisphere" – the Americas.

From BBC • Apr. 24, 2026

Trump officials have asked oil companies including Exxon Mobil, Chevron and ConocoPhillips what more they can do to push up Western Hemisphere production of oil and natural gas, according to people familiar with the matter.

From The Wall Street Journal • Mar. 26, 2026

At the time of Columbus the Western Hemisphere had been thoroughly painted with the human brush.

From "1491" by Charles C. Mann