General English

General Science

  • noun a mineral form of carbon occurring naturally as crystals or as a soft black deposit


  • The most common crystalline form of carbon, found in pencils and interstellar gas clouds

Cars & Driving

  • noun a form of carbon used in making brushes for motors and generators and as a lubricant


  • An allotropic form of the chemical element carbon. It is a soft black solid which conducts heat and electricity well. Its applications include its use as electrodes, in brushes, in electroplating, as a coating for CRTs, as a moderator in nuclear reactors, and as a lubricant.