/ Dictionary / Index B Boulder Dam: Meaning and Definition of Find definitions for: Boul'der Dam' Pronunciation: [key] a dam on the Colorado River, on the boundary between SE Nevada and NW Arizona. 726 ft. (221 m) high; 1244 ft. (379 m) long. Official name, Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. boulder clay bouldering Related Content Daily Word Quiz: sinister Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language