/ Dictionary / Index B bu.: Meaning and Definition of Find definitions for: bu. Pronunciation: [key] bureau. bushel; bushels. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. B.T.U. bub Related Content Daily Word Quiz: candor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language