/nee"on/ , n.
1. Chem. a chemically inert gaseous element occurring in small amounts in the earth's atmosphere, used chiefly in a type of electrical lamp. Symbol: Ne; at. wt.: 20.183; at. no.: 10; density: 0.9002 g/l at 0°C and 760 mm pressure.
2. See neon lamp .
3. a sign or advertising sign formed from neon lamps.
adj.
4. using or containing the gas neon.
5. made of or formed by a neon lamp or lamps: a neon sign.
6. of, pertaining to, or characteristic of a tawdry urban district or of gaudy nighttime entertainment.
[ 1895-1900; néon new, recent (neut. of néos ); see -ON 1 ]