Nī'troŭs, a.

a. [Lat. nitrosus, Fr. nitreux, Pr. nitros, Sp., Pg., & It. nitroso. See NITER.] Pertaining to, or containing, niter; partaking of the qualities of niter, or resembling it.

Nitrous acid (Chem.), an acid composed of nitrogen and oxygen, in which the oxygen is in a lower proportion than that in which the same elements form nitric acid. — Nitrous oxide, a gas composed of one equivalent of oxygen and one of nitrogen; — sometimes, from its effects on the animal system when inhaled, called exhilarating or laughing gas.