a very hard brittle bluish-white metal occurring with platinum and alloyed with iridium in osmiridium: used to produce platinum alloys, mainly for pen tips and instrument pivots, as a catalyst, and in electric-light filaments. Symbol: Os; atomic no: 76; atomic wt: 190.2; valency: 0 to 8; relative density: 22.57; melting pt: 3033±30°C; boiling pt: 5012±100°C
WordReference Random House Unabridged Dictionary of American English © 2025
os•mi•um
(oz′mē əm),USA pronunciation n. [Chem.]
- Chemistrya hard, heavy, metallic element having the greatest density of the known elements and forming octavalent compounds, as OsO4 and OsF8: used chiefly as a catalyst, in alloys, and in the manufacture of electric-light filaments. Symbol: Os;
at. wt.: 190.2;
at. no.: 76;
sp. gr.: 22.57.
- Greek osm(é̄) smell + -ium -ium; named from the penetrating odor of one of its oxides
- Neo-Latin
- 1795–1805
Collins Concise English Dictionary © HarperCollins Publishers::
'osmium' also found in these entries (note: many are not synonyms or translations):
Os
- Tennant
- ferrocene
- iridosmine
- os
- osmic
- osmious
- osmiridium
- osmium tetroxide
- platina
- platinum metal