Webster's Revised Unabridged Dictionary · 1913

Osmious

Osmious , adjective

(Chemistry) Denoting those compounds of osmium in which the element has a valence relatively lower than in the osmic compounds; as, osmious chloride.
Collocations (1)
Osmious acid (Chemistry) , (Chemistry), an acid derived from osmium, analogous to sulphurous acid, and forming unstable salts. It is a brown amorphous substance.