Alright, so since no one seems to actually understand the meaning of this word, I will give the definition that Disney gave.
Main Entry: supercalifragilisticexpialidocious
Part of Speech: adjective
Definition: a nonsense word meaning fantastic; also called supercalifragilistic
Etymology: popularized by the movie `Mary Poppins'
Does not mean frustrating, although it can be a bitch to spell. People who use this world on a daily basis are probably insane. Please aproach these people with caution.
Mom: "Hey daughter! How are you on this fine day?"
Daughter: "I am supercalifragilisticexpealidocious mother! Thank you for asking!!!!"
even though the sound of it is something quite atrocious
if you say it loud enough you'll always sound precocious