carbon
//ˈkɑːrbən//
Noun
1
A chemical element with symbol C and atomic number 6, a nonmetal that forms the basis of all organic compounds and is found in all living organisms
Carbon is essential for all life on Earth.
2
A sheet of carbon paper used for making copies of documents
She placed a carbon between the two sheets to make a copy.
3
A carbon copy or duplicate
Please keep a carbon of this letter for your records.