Osmous vs. Osmium

Difference Between Osmous and Osmium
Osmousadjective
Relating to or containing osmium in a compound with a valence lower than that in a comparable osmic compound.
Osmiumnoun
A bluish-white, hard, brittle and extremely dense metallic element, found in small amounts in osmiridium, nickel, and platinum ores. It is used as a platinum hardener and in making pen points, phonograph needles, instrument pivots, and other wear-resistant items. Atomic number 76; atomic weight 190.2; melting point 3,033°C; boiling point 5,012°C; specific gravity 22.587; valence 2, 3, 4, 6, 8. See Periodic Table.
Osmiumnoun
A chemical element (symbol Os) with atomic number 76: a hard, brittle, heavy, bluish-white transition metal found as a trace element in alloys, mostly in platinum ores.
Osmiumnoun
(countable) A single atom of this element.
Osmiumnoun
a hard brittle blue-gray or blue-black metallic element that is one of the platinum metals; the heaviest metal known