Webster's Revised Unabridged Dictionary · 1913

Nitrous

Nitrous , adjective

[Latin nitrosus full of natron: compare French nitreux. See Niter.]

1.
Of, pertaining to, or containing, niter; of the quality of niter, or resembling it.
2.
(Chemistry) Of, pertaining to, or designating, any one of those compounds in which nitrogen has a relatively lower valence as contrasted with nitric compounds.
Collocations (2)
Nitrous acid (Chemistry) , a hypothetical acid of nitrogen HNO2, not known in the free state, but forming a well known series of salts, namely, the nitrites.
Nitrous oxide , See Laughing gas.