Ni·tro·prus·sic a.  Chem. Pertaining to, derived from, or designating, a complex acid called nitroprussic acid, obtained indirectly by the action of nitric acid on potassium ferrocyanide (yellow prussiate), as a red crystalline unstable substance.  It forms salts called nitroprussides, which give a rich purple color with alkaline sulphides.
  ◄ ►