osmio-comb. form of osmium, in names of chemical compounds in which osmium and another element enter into combination with a third, as osmio-chloride, osmio-cyanide. Also used in other words, as osmiophilic a.1862Miller Elem.Chem. (ed. 2) III. 692 Osmio-cyanides and Ruthenio-cyanides may..be obtained, corresponding in composition to the ferrocyanides.1877Watts Fownes' Chem. (ed. 12) I. 531 Sodium osmiochloride, OsCl4.2NaCl, prepared by heating a mixture of osmium sulphide and sodium chloride in a current of chlorine.