Carbon meaning : The chemical element (symbol C) with an atomic number of 6. It can be found in pure form for example as graphite, a black, shiny and very soft material, or diamond, a colourless, transparent, crystalline solid and the hardest known material. An atom of this element, in reference to a molecule containing it. A sheet of carbon paper. A carbon copy. A fossil fuel that is made of impure carbon such as coal or charcoal. Carbon dioxide, in the context of global warming and climate change. A carbon rod or pencil used in an arc lamp. A plate or piece of carbon used as one of the elements of a voltaic battery. To cause (someone) to receive a carbon copy of an email message.