Supercalifragilisticexpialidocious (pronounced /ˌsuːpɚˌkælɪˌfrædʒəlˌɪstɪkˌɛkspiːˌælɪˈdoʊʃəs/) is an English word in the song with the same title in the musical film Mary Poppins. The song was written by the Sherman Brothers, and sung by Julie Andrews and Dick van Dyke.
Since Mary Poppins was a period piece set in 1910, period sounding songs were wanted. Supercalifragilisticexpialidocious sounds like popular folk songs "Boiled Beef and Carrots" and "Any Old Iron".
Based on the word's usage in song form, it can be inferred that it's an adjective.
Supercalifragilisticexpialidocious is a nonsense word. The critics' belief that the word itself has obscure origins has created some argument about when it was first used historically. According to Richard M. Sherman, co-writer of the song with his brother, Robert, the word was created by them in two weeks, mostly out of double-talk.
Roots of the word have been defined as follows: super- "above", cali- "beauty", fragilistic- "delicate", expiali- "to atone", and docious- "educable", with the sum of these parts signifying roughly "Atoning for educability through delicate beauty." This explication of its connotations suits the nature of Mary Poppins, who presents herself as both extremely beautiful and also supremely intelligent and capable of great achievements. However, it should be noted that although the word contains recognizable English morphemes, it does not follow the rules of English morphology as a whole. The morpheme -istic is a suffix in English, whereas the morpheme ex- is typically a prefix; so following normal English morphological rules, it would represent two words: supercalifragilistic and expialidocious. As one word, it also violates the rule that the letter c cannot sound like a k when followed by an e, an i or a y.
Additionally, according to the 1964 Walt Disney film, it's defined as "what you say when you don't know what to say".
In the 1942 movie "The Undying Monster" (directed by John Brahm), the character Rob Curtis (played by James Ellison) says of character Christy, "She has an overactive supercalifragilis." He goes on to define the word as "female intuition." This passage does not appear in the 1936 novel by Jessie Douglas Kerruish. The screenplay was written by Lillie Hayward and Michael Jacoby.
In popular culture
When Inverness Caledonian Thistle FC remarkably beat Celtic FC in the Scottish Cup 3-1 in February 2000 The Sun reported the story with the headline "Super Caley go ballistic, Celtic are atrocious".