Os"mi*ous (?), a. Chem.
Denoting those compounds of osmium in which the element has a valence relatively lower than in the osmic compounds; as, osmious chloride.
[Written also osmous
Osmious acid Chem., an acid derived from osmium, analogous to sulphurous acid, and forming unstable salts. It is a brown amorphous substance.
© Webster 1913.