1. An abundant nonmetallic tetravalent element occurring in three allotropic forms: amorphous carbon and graphite and diamond; occurs in all organic compounds
   "Carbon, atomic number 6, is the basis of all known life";
   - C, atomic number 6
    
2. A thin paper coated on one side with a dark waxy substance (often containing carbon); used to transfer characters from the original to an under sheet of paper
   "Before photocopiers, carbon paper was widely used to make duplicate copies of documents";
   - carbon paper
    
3. A copy made with carbon paper
   "Before photocopiers, secretaries often made carbon copies of important documents";
   - carbon copy
    
4. Fossil fuel use, regarded as a contributor to global warming; the amount of carbon dioxide contributed to the atmosphere by a process or activity, or the amount of carbon in the carbon dioxide released
   "The company aimed to reduce its carbon footprint"

Derived forms: carbons

Type of: copy, nonmetal, paper

Part of: black gold [informal], coal, crude, crude oil, fossil oil, limestone, oil, petroleum, rock oil

Encyclopedia: Carbon, Pennsylvania