Definition of "folly" []

• A lack of good sense, understanding, or foresight. (noun)
• An act or instance of foolishness: regretted the follies of his youth. (noun)
• A costly undertaking having an absurd or ruinous outcome. (noun)
• An elaborate theatrical revue consisting of music, dance, and skits. (noun)
• Obsolete Perilously or criminally foolish action. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "III. i.75 (201,2) [But wise-men's folly fall'n] Sir Thomas Hammer reads, _folly shewn_."
• "I. ii.23 (14,4) his valour is crushed into folly] To be _crushed into folly_, is to be _confused_ and mingled with _folly_, so as that they make one mass together."
• "And if any offer of alliance or parley of individual elders comes from home, the false spirits shut the gates of the castle and permit no one to enter, — there is a battle, and they gain the victory; and straightway making alliance with the desires, they banish modesty, which they call folly, and send temperance over the border."