Carbon (noun)

1. A 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.
2. A sheet of carbon paper.

Origin:

Late middle english: from old french, or from latin carbo, carbon- "charcoal, coal", from carbare "to burn, char".

Examples:

1. Carbon is a crucial element in the formation of all living things.
2. The diamond was made of carbon.
3. The graphite in a pencil is carbon.
4. He wrote a letter using carbon paper.
5. The carbon in coal is used to generate electricity.