Supercalifragilisticexpialidocious is a great word—phrase even—simply because of how fun it is to say.
Songwriter Robert B. Sherman, core writer for several Disney musicals, gained most of his fame for creating the word. During his childhood, Sherman made up words with his brother. He created this word by starting with the words "atrocious" and "precocious." Then "supercalifragilisticexpialidocious" made its official debut in the musical Mary Poppins in 1964.
The word "supercalifragilisticexpialidocious" has no meaning, according to Sherman. The song in which the word appears is meant to be funny and contains many jokes, rhymes, length, and syllables. Sherman's songbook also includes Jungle Book & The Aristocats
Although it is a mouthful, the word "supercalifragilisticexpialidocious" is extra fun to say. If you haven't repeated it out loud already, make sure you give it a try!
[Source: BBC News]