Wasium

from The Collaborative International Dictionary of English v.0.48

Wasium \Wa"si*um\, n. [NL. So called from Wasa, or Vasa, the
   name of a former royal family of Sweden.] (Chem.)
   A rare element supposed by Bahr to have been extracted from
   wasite, but now identified with thorium.
   [1913 Webster]