/ Dictionary / Index B bonanza: Meaning and Definition of Find definitions for: bo•nan•za Pronunciation: (bu-nan'zu, bō-), [key] — n. a rich mass of ore, as found in mining. a source of great and sudden wealth or luck; a spectacular windfall: The play proved to be a bonanza for its lucky backers. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: bonanza (Thesaurus) bon ami* Bonaparte Related Content Daily Word Quiz: fabricate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language