terbium Meaning, Definition & Usage

  1. noun a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite
    Tb; atomic number 65.

WordNet

Ter"bi*um noun
Etymology
NL., fr. Ytterby, in Sweden. See Erbium.
Definitions
  1. (Chem.) A rare metallic element, of uncertain identification, supposed to exist in certain minerals, as gadolinite and samarskite, with other rare ytterbium earth. Symbol Tr or Tb. Atomic weight 150.

Webster 1913