erbium erbia • erd · · · Info · Definitions · Synonyms · Characters · · erbium · · Text Latin · · Script 6 · · Length Definitions · · · (noun) a trivalent metallic element of the rare earth group; occurs with yttrium. Synonyms: Er, atomic number 68. · · Noun Definition 1 Synonyms · · · er · · Synonym 1 atomic number 68 · · Synonym 2 Characters · · b latin small letter b U+0062 e latin small letter e U+0065 i latin small letter i U+0069 m latin small letter m U+006D r latin small letter r U+0072 u latin small letter u U+0075