The destruction of perfectly good jokes is an entire Wikipedia genre! Witness the Wikipedia entry on nonexistent words used in 'The Simpson's'. We learn that Kwyjibo is a fictional word used by Bart in a game of scrabble, and then with perfect joke killing bored delivery:
Humorously enough, earlier in that same episode, Homer moans words to the effect of "How could anyone form a good word out of these letters?" His Scrabble letters spell OXIDIZE, and were arranged in that order. The word would be worth a minimum of 74 points, including 50 points for using all his letters.
This breaks the very important joke telling rule on not stretching 1 second visual jokes across entire sentences.
(That the article exists on the other hand is one more point i Wikipedias favour over traditional dictionaries)