Er"bi*um (?), n. [NL. Named from Ytterby, in Sweden, where gadolinite is found. Cf. Terbium, Yttrium, Ytterbium.] (Chem.) A metallic element of the rare earth group, found in gadolinite and some other minerals. Symbol, Er; at. wt. 167.4. Its salts are rose-colored and give characteristic spectra.

Er"bi*um (?), n. [NL. from Ytterby, in Sweden, where gadolinite is found. Cf. Terbium, Yttrium, Ytterbium.] (Chem.) A rare metallic element associated with several other rare elements in the mineral gadolinite from Ytterby in Sweden. Symbol Er. Atomic weight 165.9. Its salts are rose-colored and give characteristic spectra. Its sesquioxide is called erbia.

Er"bi*um (?), n. [NL. Named from Ytterby, in Sweden, where gadolinite is found. Cf. Terbium, Yttrium, Ytterbium.] (Chem.) A metallic element of the rare earth group, found in gadolinite and some other minerals. Symbol, Er; at. wt. 167.4. Its salts are rose-colored and give characteristic spectra.

• a metallic chemical element (symbol Er) with an atomic number of 68.
  

German
• erbium