Return to Thorium (definition)
Tho"ri*um (?), n. [NL. See [Thorite].] [Chemistry|Chem.]
A metallic element found in certain rare minerals, as thorite, pyrochlore, monazite, etc., and isolated as an infusible gray metallic powder which burns in the air and forms thoria; -- formerly called also [thorinum]. Symbol Th. Atomic weight 232.0.
© [Webster 1913].