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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

Mr. Treviño is senior director for the Western Hemisphere Initiative at the America First Policy Institute and chief transformation officer at the Texas Public Policy Foundation.

From The Wall Street Journal • Apr. 24, 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

U.S. focus on the Western Hemisphere and Mexico’s policy alignment are attracting significant investor capital and optimism.

From Barron's • Mar. 30, 2026

The goal is to better understand groundwater beneath the Great Salt Lake, the largest terminal lake in the Western Hemisphere.

From Science Daily • Mar. 21, 2026

True, he belonged to that category of people whose ancestors had inhabited the Western Hemisphere for thousands of years.

From "1491" by Charles C. Mann