saltpeter
nounIn the tobacco industry, a white saline efflorescence on the midvein and lateral ribs of the curing leaf, consisting usually of a mixture of several salts, sometimes with only a trace of saltpeter. It is thought to be developed by dry weather during the first stages of curing.
nounA salt called also
Potassium nitrate; niter; a white crystalline substance, KNO3, having a cooling saline taste, obtained by leaching from certain soils in which it is produced by the process of nitrification (see
sodium nitrate (distinguished from potassium nitrate, or true salpeter), a white crystalline substance, NaNO3, having a cooling, saline, slightly bitter taste. It is obtained by leaching the soil of the rainless districts of Chili and Peru. It is deliquescent and cannot be used in gunpowder, but is employed in the production of nitric acid. Called also
nitric acid; — sometimes so called because made from saltpeter.
nounAlternative spelling of
(KNO3) used especially as a fertilizer and explosive