1. a metallic element of the rare earth group; used in lasers; occurs in apatite and monazite and xenotime and ytterbite; [syn: terbium, Tb, atomic number 65]
WordNet (r) 3.0 (2006):
atomic number 65
n 1: a metallic element of the rare earth group; used in lasers;
occurs in apatite and monazite and xenotime and ytterbite
[syn: terbium, Tb, atomic number 65]