carbon

noun

• 1the chemical element of atomic number 6, a nonmetal that has two main forms (diamond and graphite) and that also occurs in impure form in charcoal, soot, and coal. (Symbol: C)
• [usually as modifier] carbon fiber:a bike with a carbon frame
• a rod of carbon in an arc lamp.
• a piece of carbon paper or a carbon copy.

• 2carbon dioxide or other gaseous carbon compounds released into the atmosphere, associated with climate change:the level of carbon in the atmosphere has been consistently rising [as modifier]:fossil fuel consumption and carbon emissions continued to rise