/ Dictionary / Index B black locust: Meaning and Definition of Find definitions for: black' lo'cust Pronunciation: [key] Also calleda North American tree, Robinia pseudoacacia, of the legume family, having pinnate leaves and clusters of fragrant white flowers. See Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. blacklist black lung Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language