/ Dictionary / Index B boron carbide: Meaning and Definition of Find definitions for: bo'ron car'bide Pronunciation: [key] — Chem. Chem. a black, crystalline, extremely hard, water-insoluble solid, BC, used chiefly as a moderator in nuclear reactors, as an abrasive, and as a refractory. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. boron boron hydride Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language