The Collaborative International Dictionary of English v.0.48:

Noble \No"ble\, a. [Compar. Nobler; superl. Noblest.] [F.
   noble, fr. L. nobilis that can be or is known, well known,
   famous, highborn, noble, fr. noscere to know. See know.]
   1. Possessing eminence, elevation, dignity, etc.; above
      whatever is low, mean, degrading, or dishonorable;
      magnanimous; as, a noble nature or action; a noble heart.
      [1913 Webster]

            Statues, with winding ivy crowned, belong
            To nobler poets for a nobler song.    --Dryden.
      [1913 Webster]

   2. Grand; stately; magnificent; splendid; as, a noble
      edifice.
      [1913 Webster]

   3. Of exalted rank; of or pertaining to the nobility;
      distinguished from the masses by birth, station, or title;
      highborn; as, noble blood; a noble personage.
      [1913 Webster]

   Note: Noble is used in the formation of self-explaining
         compounds; as, noble-born, noble-hearted, noble-minded.
         [1913 Webster]

   Noble gas (Chem.), 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.

   Noble metals (Chem.), silver, gold, and platinum; -- so
      called from their resistance to oxidation by air and to
      dissolution by acids. Copper, mercury, aluminium,
      palladium, rhodium, iridium, and osmium are sometimes
      included.
      [1913 Webster]

   Syn: Honorable; worthy; dignified; elevated; exalted;
        superior; sublime; great; eminent; illustrious;
        renowned; stately; splendid; magnificent; grand;
        magnanimous; generous; liberal; free.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Argon \Ar"gon\, n. [NL., fr. Gr. ?, neut. of ? inactive; ? priv.
   + ? work.] (Chem.)
   A colorless, odorless gas occurring in the air (of which it
   constitutes 0.93 per cent by volume), in volcanic gases,
   etc.; -- so named on account of its inertness by Rayleigh and
   Ramsay, who prepared and examined it in 1894-95. Symbol, A;
   at. wt., 39.9. Argon is condensible to a colorless liquid
   boiling at -186.1[deg] C. and to a solid melting at
   -189.6[deg] C. It has a characteristic spectrum. No compounds
   of it are known, but there is physical evidence that its
   molecule is monatomic. Weight of one liter at 0[deg] C. and
   760 mm., 1.7828 g.
   [Webster 1913 Suppl.]

WordNet (r) 3.0 (2006):

argon
    n 1: a colorless and odorless inert gas; one of the six inert
         gases; comprises approximately 1% of the earth's atmosphere
         [syn: argon, Ar, atomic number 18]

The Elements (07Nov00):

argon
Symbol: Ar
Atomic number: 18
Atomic weight: 39.948
Monatomic noble gas. Makes up 0.93% of the air. Colourless, odorless. Is
inert and has no true compounds. Lord Rayleigh and Sir William Ramsey
identified argon in 1894.