carbon

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A naturally abundant nonmetallic element that occurs in many inorganic and in all organic compounds, exists freely as graphite and diamond and as a constituent of coal, limestone, and petroleum, and is capable of chemical self-bonding to form an enormous number of chemically, biologically, and commercially important molecules. Atomic number 6; atomic weight 12.011; sublimation point above 3,500°C; boiling point 4,827°C; specific gravity of amorphous carbon 1.8 to 2.1, of diamond 3.15 to 3.53, of graphite 1.9 to 2.3; valence 2, 3, 4. See Table at element.
2. n. A sheet of carbon paper.
3. n. A carbon copy.
4. n. Electricity Either of two rods through which current flows to form an arc, as in lighting or welding.
5. n. Electricity A carbonaceous electrode in an electric cell.

Century Dictionary and Cyclopedia

1. n. Chemical symbol, C; atomic weight, 11.97. An element found in nature in two distinct forms: the diamond, which is extremely hard, of high specific gravity (3.5), usually colorless and transparent, with brilliant adamantine luster, and crystallizes in octahedrons; and graphite, which is very soft, of low specific gravity , black and opaque, with metallic luster, and crystallizes in hexagonal plates. See diamond and graphite. Its physical properties vary greatly with its different forms. It is combustible, burning to carbonic acid (CO₂). In combination it is universally distributed through the animal and vegetable kingdoms being a constituent of every living tissue. By the action of heat on such tissues, with partial or complete exclusion of air, carbon is procured in amorphous form more or less mixed with other matters. Such products are animal charcoal, lampblack, wood charcoal, coke, and gas-carbon. The number of its compounds with the other elements is endless; and at present more compounds of carbon are known, probably, than of all other elements taken together. It is present in the atmosphere as carbon dioxid, or carbonic-acid gas, and in the same form in some mineral waters; it also appears in the salts called carbonates, as calcium carbonate in coral, in the shells of many sea-animals, in the common mineral calcite, including chalk, limestone, marble, etc., and as iron carbonate in the mineral siderite, etc.
2. n. The form of diamond generally called carbonado; the black diamond.
3. n. In electric lighting, a carbon-point (see below).
4. To put carbons in (an arc lamp).

Wiktionary

1. n. uncountable The chemical element (symbol C) with an atomic number of 6.
2. n. countable, informal A sheet of carbon paper.
3. n. countable, informal A carbon copy.
4. n. A fossil fuel that is made of impure carbon such as coal or charcoal.
5. n. ecology, uncountable Carbon dioxide, in the context of global warming and climate change.

GNU Webster's 1913

1. n. (Chem.) An elementary substance, not metallic in its nature, which is present in all organic compounds. Atomic weight 11.97. Symbol C. it is combustible, and forms the base of lampblack and charcoal, and enters largely into mineral coals. In its pure crystallized state it constitutes the diamond, the hardest of known substances, occuring in monometric crystals like the octahedron, etc. Another modification is graphite, or blacklead, and in this it is soft, and occurs in hexagonal prisms or tables. When united with oxygen it forms carbon dioxide, commonly called carbonic acid, or carbonic oxide, according to the proportions of the oxygen; when united with hydrogen, it forms various compounds called hydrocarbons. Compare diamond, and graphite.
2. n. (Elec.) A carbon rod or pencil used in an arc lamp; also, a plate or piece of carbon used as one of the elements of a voltaic battery.
3. n. a sheet of carbon paper.
4. n. a carbon copy.

WordNet 3.0

1. n. a copy made with carbon paper
2. n. an abundant nonmetallic tetravalent element occurring in three allotropic forms: amorphous carbon and graphite and diamond; occurs in all organic compounds
3. n. 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