Western Hemisphere
noun
the western part of the terrestrial globe, including North and South America, their islands, and the surrounding waters.
that half of the earth traversed in passing westward from the prime meridian to 180° longitude.
British Dictionary definitions for western hemisphere
western hemisphere
noun (often capitals)
that half of the globe containing the Americas, lying to the west of the Greenwich or another meridian
the lands contained in this, esp the Americas
Scientific definitions for western hemisphere
Western Hemisphere
[ wĕs′tərn ]
The half of the Earth that includes North America, Central America, and South America, as divided roughly by the 0° and 180° meridians. See more at prime meridian.