A rare metallic element of the boron-aluminium group, found in gadolinite and other rare minerals, and extracted as a dark gray powder. Symbol Y. Atomic weight, 89.
a metallic element with atomic number 39 usually included in the rare-earth group that occurs usually with other rare earth elements in minerals and is used especially in phosphors, YAG lasers, alloys, and treatments for certain cancers see Chemical Elements Table