An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A very hard, brittle metal belonging to the → platinum group elements; symbol Os. → Atomic number 76, → atomic weight 190.2, → melting point 3,045 °C, → boiling point 5,027 °C, → specific gravity 22.57 at 20°C. It was discovered in 1803 simultaneously with → iridium in a crude → platinum ore by the English chemist Smithson Tennant.

From Gk. osme "smell" because of the sharp odor of the volatile oxide.