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ne·on (nēŏn)
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n.
1. Symbol Ne A rare, inert gaseous element occurring in the atmosphere to the extent of 18 parts per million and obtained by fractional distillation of liquid air. It is colorless but glows reddish orange in an electric discharge and is used in lasers, as a cryogen, and in cathode-ray tubes and other display devices. Atomic number 10; atomic weight 20.180; melting point -248.59°C; boiling point -246.08°C. See Periodic Table.
2. Electric signage made with neon lights.
3. An extremely bright shade of a color.
4. A neon tetra.
adj.
1. Of, relating to, or containing neon.
2. Of or relating to a form of lighting used especially on advertising signs and consisting of glass tubes filled with neon or other gases that emit colored light when subjected to an electric current.
3. Extremely bright or vivid; fluorescent: neon purple.

[From Greek, neuter of neos, new; see newo- in the Appendix of Indo-European roots.]
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neon

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2017 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
 

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