Lutetium /(?)/

Lu·te·ti·um

Lutetium

n.
  1. A metallic element separated from ytterbium in 1907, by Urbain in Paris and by von Welsbach in Vienna. It is a member of the Lanthanide rare earth group. Symbol, Lu; atomic number 71; atomic weight 174.967 [C=12.011]. Previously spelled Lutecium. (Chem.)