carbon

Etymology

Borrowed from French carbone, coined by Antoine Lavoisier, from Latin carbō, carbōnem (“charcoal, coal”), from Proto-Indo-European *kerh₃- (“to burn”).

noun

1. (uncountable) The chemical element (symbol C) with an atomic number of 6. It can be found in pure form for example as graphite, a black, shiny and very soft material, or diamond, a colourless, transparent, crystalline solid and the hardest known material.
   Carbon is the most common element in our bodies—indeed, in all living things on earth. 2006, Michael Pollan, The Omnivore's Dilemma, The Penguin Press, page 20
2. (countable) An atom of this element, in reference to a molecule containing it.
   A methane molecule is made up of a single carbon with four hydrogens.
3. (countable, informal) A sheet of carbon paper.
   He stepped back and opened his bag and took out a printed pad of D.O.A. forms and began to write over a carbon. 1939, Raymond Chandler, The Big Sleep, Penguin, published 2011, page 51
4. (countable, informal) A carbon copy.
5. A fossil fuel that is made of impure carbon such as coal or charcoal.
6. (ecology, uncountable) carbon dioxide, in the context of climate change.
   carbon neutral
   If Alberta’s reserves are a carbon bomb, this global expansion of tar sands and oil shale exploitation amounts to an escalating emissions arms race, the unlocking of a subterranean cache of weapons of mass ecological destruction. 2014-04-25, Martin Lukacs, “Canada becoming launch-pad of a global tar sands and oil shale frenzy”, in The Guardian Weekly, volume 190, number 20, page 13
7. A carbon rod or pencil used in an arc lamp.
   To trim an arc lamp, first remove the old carbons and carefully and thoroughly wipe the carbon rods, holders, &c. with a clean, dry rag. 1892, English Mechanic and World of Science, page 444
8. A plate or piece of carbon used as one of the elements of a voltaic battery.
9. (informal) Ellipsis of carbon fiber (reinforced polymer).
   carbon bike frame

verb

1. (Internet, transitive, uncommon) To cause (someone) to receive a carbon copy of an email message.
   When I send it, I'll carbon Julia so she's aware.