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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

His focus has been on the ongoing war with Iran, military operations in the Western Hemisphere and domestic concerns.

From BBC • May 11, 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

Jamaican jerk seasoning, made with allspice, cinnamon, nutmeg and cloves, is a reminder that the spice route reached all the way to the Western Hemisphere.

From The Wall Street Journal • Apr. 17, 2026

When microbes arrived in the Western Hemisphere, he argued, they must have swept from the coastlines first visited by Europeans to inland areas populated by Indians who had never seen a white person.

From "1491" by Charles C. Mann