: any of several compounds (as potassium cyanide) that contain the radical CN having a chemical valence of one, react with and inactivate respiratory enzymes, and are rapidly lethal producing drowsiness, tachycardia, coma, and finally death
Any chemical compound containing the combining group CN. Ionic (seeion; ionic bond) and organic cyanide compounds differ in chemical properties, but both are toxic, especially the ionic ones. Cyanide poisoning inhibits cells' oxidative (seeoxidation-reduction) processes; its action is extremely rapid, and an antidote must be given promptly. Cyanides occur naturally in certain seeds (e.g., apple seeds, wild cherry pits). Cyanides, including hydrogen cyanide (HCN, or hydrocyanic acid), are used industrially in the production of acrylic fibres, synthetic rubbers, and plastics as well as in electroplating, case-hardening of iron and steel, fumigation, and concentration of ores.