er|bi|um

er|bi|um «UR bee uhm», noun.

a grayish, rare-earth metallic chemical element of the yttrium group. It is soft and lustrous, occurs as a minute part of various minerals, and is used in nuclear research.

╂[< New Latin erbium < (Ytt)erby, a town in Sweden, where gadolinite (which contains erbium) was found]