Definition of folly

• n. - The state of being foolish; want of good sense; levity, weakness, or derangement of mind.
• n. - A foolish act; an inconsiderate or thoughtless procedure; weak or light-minded conduct; foolery.
• n. - Scandalous crime; sin; specifically, as applied to a woman, wantonness.
• n. - The result of a foolish action or enterprise.