(Chem.) A prefix, or combining form, indicating ferrous iron as an ingredient; as, ferrocyanide. [ 1913 Webster ]

n. [ Ferro- + calcite. ] Limestone containing a large percentage of iron carbonate, and hence turning brown on exposure. [ 1913 Webster ]

n. (Arch. & Engin.) Concrete strengthened by a core or foundation skeleton of iron or steel bars, strips, etc. Floors, columns, piles, water pipes, etc., have been successfully made of it. Called also armored concrete steel, and most commonly reenforced concrete. [ Webster 1913 Suppl. +PJC ]

n. [ Ferro- + cyanate: cf. F. ferrocyanate. ] (Chem.) A salt of ferrocyanic acid; a ferrocyanide. [ 1913 Webster ]

a. [ Ferro- + cyanic: cf. F. ferrocyanique. ] (Chem.) Pertaining to, derived from, or designating, a ferrocyanide. [ 1913 Webster ]

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. [ 1913 Webster ]

n. [ Ferro- + cyanide. ] (Chem.) One of a series of complex double cyanides of ferrous iron and some other base. [ 1913 Webster ]

Potassium ferrocyanide (Chem.), yellow prussiate of potash; a tough, yellow, crystalline salt, K4(CN)6Fe, the starting point in the manufacture of almost all cyanogen compounds, and the basis of the ferric ferrocyanate, prussian blue. It is obtained by strongly heating together potash, scrap iron, and animal matter containing nitrogen, as horn, leather, blood, etc., in iron pots. [ 1913 Webster ]

n. [ Ferro- + prussiate. ] (Chem.) A ferrocyanate; a ferocyanide. [ R. ] [ 1913 Webster ]

a. [ Ferro- + prussic. ] (Chem.) Ferrocyanic. [ 1913 Webster ]

(Chem.) See Ferro-. [ 1913 Webster ]

n. [ L. ferrum iron + -type. ] A photographic picture taken on an iron plate by a collodion process; -- familiarly called tintype. [ 1913 Webster ]