/ Dictionary / Index B black acacia: Meaning and Definition of Find definitions for: black' aca'cia Pronunciation: [key] a tall Australian tree, Acacia melanoxylon, of the legume family, having cream-yellow flowers and yielding a very light wood. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. black blackacre 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