What does "ferrocyanic" mean?

Ferrocyanic: Pertaining to, derived from, or designating, a ferrocyanide. ferrocyanic acid (Chem.), a white crystalline substance, H4(CN)6Fe, of strong acid properties, obtained from potassium ferrocyanide, and regarded as the type of the ferrocyanides; -- called also hydro- ferrocyanic acid, hydrogen ferrocyanide. etc.

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