from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Any of the elements in Group O of the periodic table, including helium, neon, argon, krypton, xenon, and radon, which are monatomic and with limited exceptions chemically inert. Also called inert gas.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Any of the elements of group 18 of the periodic table, being monatomic and (with very limited exceptions) inert.
from the GNU version of the Collaborative International Dictionary of English
- adj. a gaseous element belonging to group VIII of the periodic table of elements, not combining with other elements under normal reaction conditions; specifically, helium, neon, argon, krypton, xenon, or radon; also called inert gas.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. any of the chemically inert gaseous elements of the helium group in the periodic table
Sorry, no etymologies found.