"What's the longest word in the dictionary?"
"You mean -- the longest English word."
"Well, that depends which dictionary you go for. Bigger dictionaries have more words in them, and smaller dictionaries have fewer words in them. There's more chance of bigger dictionaries having longer words. You takes your choice."
"Long Words In The OED,"
Word Ways: Vol. 30
, Article 9.
Available at: http://digitalcommons.butler.edu/wordways/vol30/iss4/9