Source : Webster's Revised Unabridged Dictionary (1913)

Polonium \Po*lo"ni*um\, n. [NL. So named after Poland, in L.
   form Polonia, one of the discoverers being a Pole.] (Chem.)
   A supposed new element, a radioactive substance discovered by
   M. and MMe. Curie in pitchblende. It is closely related
   chemically to bismuth. It emits only alpha rays and is
   perhaps identical with radium F.

Source : WordNet®

polonium
     n : a radioactive metallic element that is similar to tellurium
         and bismuth; occurs in uranium ores but can be produced
         by bombarding bismuth with neutrons in a nuclear reactor
         [syn: {Po}, {atomic number 84}]