folly

[ fol-ee ]
/ ˈfɒl i /

noun, plural fol·lies for 2–6.

the state or quality of being foolish; lack of understanding or sense.
a foolish action, practice, idea, etc.; absurdity: the folly of performing without a rehearsal.
a costly and foolish undertaking; unwise investment or expenditure.
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.
follies, a theatrical revue.
Obsolete. wickedness; wantonness.

Origin of folly

1175–1225; Middle English folie < Old French, derivative of fol, fou foolish, mad. See fool1
Related formssu·per·fol·ly, noun, plural su·per·fol·lies.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for follies

British Dictionary definitions for follies

folly

/ (ˈfɒlɪ) /

noun plural -lies

the state or quality of being foolish; stupidity; rashness
a foolish action, mistake, idea, etc
a building in the form of a castle, temple, etc, built to satisfy a fancy or conceit, often of an eccentric kind
(plural) theatre an elaborately costumed revue
archaic
  1. evil; wickedness
  2. lewdness; wantonness

Word Origin for folly

C13: from Old French folie madness, from fou mad; see fool 1
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012