/ Dictionary / Index W Western Hemisphere: Meaning and Definition of Find definitions for: West'ern Hem'isphere Pronunciation: [key] 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. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Western Han western hemlock Related Content Daily Word Quiz: hedonist Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language