(mineralogy) Any of several alkaline feldspars containing potassium aluminium silicate, KAlSi₃O₈

(physics) The major stable isotope of potassium, ³⁹₁₉K, having nineteen protons and twenty neutrons; it amounts to over 93% of the element in nature

(inorganic chemistry) The salt KNbO₃; its crystals have a large nonlinear optical coefficient, and it find use in the manufacture of lasers; nanowires of the substance have been used to produce tunable coherent light.

(inorganic chemistry) The potassium salt of hydrochloric acid, KCl; it is used as a fertilizer, and in lethal injections

(inorganic chemistry) The alkaline salt K₂CO₃, that is the major constituent of potash; it is used in the production of glass and some soaps.

(inorganic chemistry) The alkaline base KOH, once known as caustic potash; it has a number of industrial uses, including the manufacture of bleach.

A particular artificial sweetener.

The artificial sweetener, potassium 6-methyl-2,2-dioxo-oxathiazin-4-olate

cream of tartar

(inorganic chemistry) An odorless, slightly basic substance which is soluble in water and often used to offset acidity.