/ Dictionary / Index W western hemlock: Meaning and Definition of Find definitions for: west'ern hem'lock Pronunciation: [key] a tall, narrow hemlock, Tsuga heterophylla, of western North America: the state tree of Washington. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Western Hemisphere Western Hindi 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