"Supercalifragilisticexpialidocious"

The word itself has obscure origins, pertaining as to when it was first used, but the roots are fairly clear, as Richard Lederer wrote in his book Crazy English: super- "above," cali- "beauty," fragilistic- "delicate," expiali- "to atone," and docious- "educable," the sum meaning roughly "Atoning for extreme and delicate beauty while still being highly educable." This is the perfect word for Mary Poppins to use, being that she thinks of herself as incredibly beautiful but also extremely intelligent.
Spanish-supercalifragilisticoexpialidoso
German-Superkalifragilistischexpiallegorisch
Italian-supercalifragilistichespiralidoso