—n. 1. Chem.a salt or ester of nitric acid, or any compound containing the univalent group –ONO2 or NO3.
2. fertilizer consisting of potassium nitrate or sodium nitrate.
3. cellulose nitrate, a substance used as a film base in the early days of filmmaking.
4. Informal.See nitrate film.
—v.t. 1. to treat with nitric acid or a nitrate.
2. to convert into a nitrate.