rare earth rare-bred • rare-earth element · · · Info · Definitions · Synonyms · Characters · · rare earth · · Text Common · · Latin · · Scripts 10 · · Length 2 · · Syllables Definitions · · · (noun) any element of the lanthanide series (atomic numbers 57 through 71). Synonyms: rare earth, rare-earth element, lanthanoid, lanthanide, lanthanon. · · Noun Definition 1 Synonyms · · · rare-earth element · · Synonym 1 lanthanoid · · Synonym 2 lanthanide · · Synonym 3 lanthanon · · Synonym 4 Characters · · space U+0020 a latin small letter a U+0061 e latin small letter e U+0065 h latin small letter h U+0068 r latin small letter r U+0072 t latin small letter t U+0074