- a rare-earth metallic element, having pink salts. Symbol: Er; atomic weight: 167.26; atomic number: 68.
- a soft malleable silvery-white element of the lanthanide series of metals: used in special alloys, room-temperature lasers, and as a pigment. Symbol: Er; atomic no: 68; atomic wt: 167.26; valency: 3; relative density: 9.006; melting pt: 1529°C; boiling pt: 2868°C
1843, coined in Modern Latin with metallic element name -ium + erbia, name given by Swedish chemist Carl Gustaf Mosander (1797-1858), who discovered it, from second element in Ytterby, name of a town in Sweden where mineral containing it was found.
n. Symbol Er
- A soft rare-earth element, used in metallurgy and nuclear research. Atomic number 68.
- A soft, silvery, metallic element of the lanthanide series. It is used as a neutron absorber in nuclear technology and in light amplification for fiber-optic telecommunications. Atomic number 68; atomic weight 167.26; melting point 1,497°C; boiling point 2,900°C; specific gravity 9.051; valence 3. See Periodic Table.