folly
One entry found for folly.
Main Entry: fol·ly
Pronunciation: 'fä-lE
Function: noun
Inflected Form(s): plural follies
Etymology: Middle English folie, from Anglo-French, from fol fool
1 : lack of good sense or normal prudence and foresight
2 a : criminally or tragically foolish actions or conduct b obsolete : EVIL, WICKEDNESS; especially : lewd behavior
3 : a foolish act or idea
4 : an excessively costly or unprofitable undertaking5 : an often extravagant picturesque building erected to suit a fanciful taste

Merriam-Webster Online Dictionary:
http://www.m-w.com/cgi-bin/dictionary?book=Dictionary&va=folly