nitrous

adjective Chemistry.

1. pertaining to compounds obtained from niter, usually containing less oxygen than the corresponding nitric compounds.
2. containing nitrogen, usually in the trivalent state.

adjective

1. of, derived from, or containing nitrogen, esp in a low valency state

adj.c.1600, from Latin nitrosus, from nitrum (see nitre). Originally “of nitre, pertaining to nitre;” more precise use in chemistry (designating a compound in which the nitrogen has a lower valence than the corresponding nitric compound) is from 1780s. Nitrous oxide attested from 1800. adj.

1. Of, derived from, or containing nitrogen, especially in a valence state lower than that in a comparable nitric compound.

1. Containing nitrogen, especially nitrogen with a valence of 3. Compare nitric.