potassium cyanide
noun1
- The potassium salt of hydrocyanic acid, KCN; the colourless crystals are soluble in water, and it is extremely poisonous, and is used in electroplating, the extraction of gold and silver from their ores, and in photography.
- During interrogation he committed suicide by swallowing a coat-button of compressed potassium cyanide. — 1953