carbon (ˈkɑːbən) ![]() | |
| —n | |
| 1. | a. a nonmetallic element existing in the three crystalline forms: graphite, diamond, and buckminsterfullerene: occurring in carbon dioxide, coal, oil, and all organic compounds. The isotope carbon-12 has been adopted as the standard for atomic wt; carbon-14, a radioisotope with a half-life of 5700 years, is used in radiocarbon dating and as a tracer. Symbol: C; atomic no: 6; atomic wt: 12.011; valency: 2, 3, or 4; relative density: 1.8--2.1 (amorphous), 1.9--2.3 (graphite), 3.15--3.53 (diamond); sublimes at 3367±25°C; boiling pt: 4827°C |
| b. (as modifier): a carbon compound | |
| 2. | carbon paper short for carbon copy |
| 3. | a carbon electrode used in a carbon-arc light or in carbon-arc welding |
| 4. | a rod or plate, made of carbon, used in some types of battery |
| [C18: from French carbone, from Latin carbō charcoal, dead or glowing coal] | |
| 'carbonous | |
| —adj | |
| the offspring of a zebra and a donkey. |
| a screen or mat covered with a dark material for shielding a camera lens from excess light or glare. |