- a black, crystalline, extremely hard, water-insoluble solid, B4C, used chiefly as a moderator in nuclear reactors, as an abrasive, and as a refractory.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- a black extremely hard inert substance having a high capture cross section for thermal neutrons. It is used as an abrasive and refractory and in control rods in nuclear reactors. Formula: B 4 C
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012