1. Of, pertaining to, or containing, niter; of the quality of niter, or resembling it.
2. (Science: chemistry) Of, pertaining to, or designating, any one of those compounds in which nitrogen has a relatively lower valence as contrasted with nitric compounds.
(Science: chemistry) Nitrous acid, a hypothetical acid of nitrogen HNO2, not known in the free state, but forming a well known series of salts, viz, the nitrites. Nitrous oxide. See laughing gas.
Origin: L. Nitrosus full of natron: cf. F. Nitreux. See Niter.