[1] : 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
see also:
nobler noblest know noble gas helium neon 
argon krypton xenon radon inert gas 
noble metals 

[2] : WordNet (r) 2.0

noble gas
     n : any of the chemically inert gaseous elements of the helium
         group in the periodic table syn: inert gas, argonon
see also:
inert gas argonon 

Gas >> G Words
Gas, definition of term: Gas
gas_pag1.html

Gas Stove >> G Words
Gas Stove, definition of term: Gas Stove
gas+stove_pag1.html

Gas Turbine >> G Words
Gas Turbine, definition of term: Gas Turbine
gas+turbine_pag1.html

Gas Station >> G Words
Gas Station, definition of term: Gas Station
gas+station_pag1.html

Gas Jet >> G Words
Gas Jet, definition of term: Gas Jet
gas+jet_pag1.html

Gas Chamber >> G Words
Gas Chamber, definition of term: Gas Chamber
gas+chamber_pag1.html

Coal Gas >> C Words
Coal Gas, definition of term: Coal Gas
coal+gas_pag1.html