Definition of "boron carbide" []

• A compound of boron and carbon, especially B4C, an extremely hard, black crystalline compound or solid solution. It is used as an abrasive, in control rods for nuclear reactors, and as a reinforcing filament in composite structural materials. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.