aOsmiamic(Chem) Of, pertaining to, or designating, a nitrogenous acid of osmium, H2N2Os2O5, forming a well-known series of yellow salts.
Century Dictionary and Cyclopedia
osmiamicNoting an acid obtained by decomposing its barium salt with dilute sulphuric acid. It forms a yellow solution in water, which if concentrated soon undergoes decomposition. Its formula is HNO8O3, and it probably contains the nitroso-group.