\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.