potassium nitrate

American  

noun

Chemistry.

1. a crystalline compound, KNO 3 , produced by nitrification in soil, and used in gunpowders, fertilizers, and preservatives; saltpeter; niter.

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potassium nitrate British  

noun

1. Also called: saltpetre.   nitre.  a colourless or white crystalline compound used in gunpowders, pyrotechnics, fertilizers, and as a preservative for foods, esp as a curing salt for ham, sausages, etc ( E252 ). Formula: KNO 3

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potassium nitrate Scientific  

1. A transparent, white, crystalline compound and strong oxidizing agent. It is used in gunpowder and fireworks, in making glass, and in fertilizer. Also called saltpeter. Chemical formula: KNO ₃ .

2. See also niter

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Etymology

Origin of potassium nitrate

First recorded in 1880–85

Example Sentences

These included potassium sorbate, potassium metabisulfite, sodium nitrite, potassium nitrate, and acetic acid.

From Science Daily • Jan. 27, 2026

Black powder, first formulated in China more than a millennium ago, is a mixture of sulphur, carbon and potassium nitrate.

From Washington Times • Aug. 11, 2022

To keep it from melting, the ice was treated with potassium nitrate, otherwise known as saltpetre.

From Salon • Dec. 31, 2020

Gunpowder is a mixture of potassium nitrate, sulfur, and charcoal.

From Textbooks • Feb. 14, 2019

He could tell just from picking up a toothpaste tube whether it contained potassium nitrate.

From "The House of Hades" by Rick Riordan