/ Dictionary / Index L Lewis Mountains: Meaning and Definition of Find definitions for: Lew'is Moun'tains Pronunciation: [key] a mountain range in the NW United States and W Canada, in W Montana and Alberta province: part of the Rocky Mountains. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. lewisite Lewisohn Related Content Daily Word Quiz: supine Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language