<p><strong>Noun</strong></p><ul><li>Chemistry: A widely distributed element that forms organic compounds in combination with hydrogen, oxygen, etc., and occurs in a pure state as diamond and graphite, and in an impure state as charcoal.</li><li>Carbon dioxide or other carbon compounds that are emitted into the atmosphere and cause rising temperatures: the carbon produced by burning fossil fuels.</li><li>A carbon copy.</li><li>A sheet of carbon paper.</li><li>The carbon rod through which current is conducted between the electrode holder and the arc in carbon arc lighting or welding.</li><li>The rod or plate, composed in part of carbon, used in batteries.</li></ul><p><strong>Adjective</strong></p><ul><li>Pertaining to or noting the element carbon or any of its compounds, especially carbon dioxide: to reduce carbon emissions.</li></ul>