Noble gas (5)

'noble gas' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for argon that I've seen before include "Noble gas used in light bulbs" , "Organ (anag.)" , "Chemical element" , "Inert gas in atmosphere" , "Inert eighteen ac gas" .)
'noble gas' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for radon that I've seen before include "hazardous substance" , "Naturally occurring inert gas" , "Colourless gas, atomic number 86" , "Inert gas - adorn (anag)" , "Rare noble gas" .)
'noble gas' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for xenon that I've seen before include "Inert gas used in radio valves" , "Noble element" , "One of the noble gasses" , "Heavy gaseous element" , "member of nobility?" .)
'noble gas' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for neon that I've seen before include "Inert gas, symbol Ne" , "None (anag.)" , "Gaseous element, in advertising signs, say" , "Small plant; colour" , "It may illuminate" .)
(Other definitions for helium that I've seen before include "Very light, inert gas" , "Second lightest element" , "... ditto: symbol He" , "Floating balloon gas" , "Light colourless gas used in balloons" .)
'noble gas' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for krypton that I've seen before include "Chemical element, Kr" , "Pry knot (anag) - gas" , "36 periodically?" , "Inert gas (symbol Kr)" , "Noble gas, Kr" .)