/ Dictionary / Index Y Yellowstone Lake: Meaning and Definition of Find definitions for: Yel'lowstone Lake' Pronunciation: [key] a lake in NW Wyoming, in Yellowstone National Park. 20 mi. (32 km) long; 140 sq. mi. (363 sq. km). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Yellowstone Falls Yellowstone National Park Related Content Daily Word Quiz: blithesome Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language