Definition of nitrox:
(n) :
(underwater diving) A mixture of nitrogen and oxygen, the nitrogen content being lower than that of normal air, which is used in place of air as a breathing gas.
(n) :
(metallurgy) An industrial process for case hardening (imparting greater surface hardness to) metal objects, involving nitrocarburizing (the diffusion of carbon and nitrogen into the metal) followed by oxidation.