/ Dictionary / Index Y Yellowstone Falls: Meaning and Definition of Find definitions for: Yel'lowstone Falls' Pronunciation: [key] two waterfalls of the Yellowstone River, in Yellowstone National Park: upper falls, 109 ft. (33 m) high; lower falls, 308 ft. (94 m) high. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Yellowstone Yellowstone Lake Related Content Daily Word Quiz: arid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language