Pronunciation: (nē'on),[key] —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. 1. using or containing the gas neon.
2. made of or formed by a neon lamp or lamps: a neon sign. 3. of, pertaining to, or characteristic of a tawdry urban district or of gaudy nighttime entertainment.