<p><strong>Noun</strong></p><ul><li>the state or quality of being foolish; lack of understanding or sense.</li><li>a foolish action, practice, idea, etc.; absurdity.</li><li>a costly and foolish undertaking; unwise investment or expenditure.</li><li>Architecture: a whimsical or extravagant structure built to serve as a conversation piece, lend interest to a view, commemorate a person or event, etc.: found especially in England in the 18th century.</li><li>follies, a theatrical revue.</li><li>Obsolete: wickedness; wantonness.</li></ul>