Source : Webster's Revised Unabridged Dictionary (1913)

Nitrogen \Ni`tro*gen\, n. [L. nitrum natron + -gen: cf. F.
   nitrog[`e]ne. See {Niter}.] (Chem.)
   A colorless nonmetallic element, tasteless and odorless,
   comprising four fifths of the atmosphere by volume. It is
   chemically very inert in the free state, and as such is
   incapable of supporting life (hence the name {azote} still
   used by French chemists); but it forms many important
   compounds, as ammonia, nitric acid, the cyanides, etc, and is
   a constituent of all organized living tissues, animal or
   vegetable. Symbol N. Atomic weight 14. It was formerly
   regarded as a permanent noncondensible gas, but was liquefied
   in 1877 by Cailletet of Paris, and Pictet of Geneva.

Source : WordNet®

nitrogen
     n : a common nonmetallic element that is normally a colorless
         odorless tasteless inert diatomic gas; constitutes 78
         percent of the atmosphere by volume; a constituent of all
         living tissues [syn: {N}, {atomic number 7}]