thorium (n.) Look up thorium at Dictionary.com
rare metallic element, 1832, Modern Latin, named by its discoverer, Swedish chemist Jöns Jakob Berzelius (1779-1848) from thorite (silicate of thorium), the name of a mineral found in Norway from which it was extracted (which Berzelius also had named, as thoria, in 1828), and named in honor of the Scandinavian god Thor. With chemical ending -ium.