\Fer`ro*cy*an"ic\, a. [Ferro- + cyanic: cf. F.
ferrocyanique.] (Chem.)
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.