The Collaborative International Dictionary of English v.0.48:
Prussiate \Prus"si*ate\, n. [Cf. F. prussiate.] (Chem.) A salt of prussic acid; a cyanide. [1913 Webster] Red prussiate of potash. See Potassium ferricyanide, under Ferricyanide. Yellow prussiate of potash. See Potassium ferrocyanide, under Ferrocyanide. [1913 Webster]