Meaning of osmium

os•mi•um

Pronunciation: (oz'mē-um), [key]
— n. Chem.
  1. a hard, heavy, metallic element having the greatest density of the known elements and forming octavalent compounds, as OsO and OsF: 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.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.
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