Supercalifragilisticexpialidocious-
the word supposedly coined by Mary Poppins to make kids sound “precocious,” was actually invented by turn-of-the-century Scottish coal miners. It was used to request “the works” from prostitutes by men too shy to recite specific acts.
Also: 'Supercalafajalistickespeealadojus' was already a copyrighted song when Disney stole the word (with tiny variations ala Vanilla Ice) and wrote their own song, keeping all royalties. That dirty Poppins.
And now, more foreign floccinaucinihilipilification:
Lithuanian
NEBEPRISIKISKIAKOPUSTELIAUJANCIUOSIUOSE - males who aren't gathering enough wood sorrel by themselves anymore
Russian
ZAGIPNOTIZIROVAVSHEMUSYA - he who has hypnotized himself
Turkish
ÇEKOSLOVAKYALILASTIRAMADIKLARIMIZDANMISINIZ - Are you one of the people whom we couldn't Czechoslovakianize?
Hungarian
Megszentségteleníthetetlenségeskedéseitekért - for your constant mentioning of the fact that [a particular thing] is unprofanable
Mohawk
TKANUHSTASRIHSANUHWE'TSRAAKSAHSRAKARATATTSRAYERI - the praising of the evil of the liking of the finding of the house is right
Dutch
ZANDZEEPSODEMINERAALWATERSTEENSTRALEN - Go away.