Longest Words

(45) PNEUMONO­ULTRA­MICRO­SCOPIC­SILICO­VOLCANO­CONIOSIS (also spelledPNEUMONO­ULTRA­MICRO­SCOPIC­SILICO­VOLCANO­KONIOSIS) = a lung disease caused by breathing in particles of siliceous volcanic dust.
This is the longest word in any English dictionary. However, it was coined by Everett Smith, the President of The National Puzzlers' League, in 1935 purely for the purpose of inventing a new "longest word". The Oxford English Dictionary described the word as factitious. Nevertheless it also appears in the Webster's, Random House, andChambers dictionaries.

(37) HEPATICO­CHOLANGIO­CHOLECYST­ENTERO­STOMIES = a surgical creation of a connection between the gall bladder and a hepatic duct and between the intestine and the gall bladder.
This is the longest word in Gould's Medical Dictionary.

(34) SUPER­CALI­FRAGI­LISTIC­EXPI­ALI­DOCIOUS = song title from the Walt Disney movie Mary Poppins.
It is in the Oxford English Dictionary.

"But then one day I learned a word
That saved me achin' nose,
The biggest word you ever 'eard,
And this is 'ow it goes:
Supercalifragilisticexpialidocious!"

(30) HIPPOPOTO­MONSTRO­SESQUIPED­AL­IAN = pertaining to a very long word.
From Mrs. Byrne's Dictionary of Unusual, Obscure and Preposterous Words.