Thorium
Pronunciation : Tho"ri*um
Part of Speech : n.
Etymology : [NL. See Thorite.] (Chem.)
Definition : Defn: 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.
Source : Webster's Unabridged Dictionary, 1913