ˈnī.trəs adjective
Etymology: New Latin nitrosus, from Latin, full of natron, from nitrum natron + -osus -ous — more at niter
1. : of, relating to, containing, or impregnated with niter : of the nature of or like niter
nitrous powder
Priestley's name for nitric oxide was nitrous air
2. : of, relating to, or containing nitrogen — used especially of compounds in which this element has a lower valence than in corresponding nitric compounds
nitrous oxide
nitrous acid