folly

American  

[fol-ee] / ˈfɒl i /

noun

• follies
  plural

1. the state or quality of being foolish; lack of understanding or sense.

2. a foolish action, practice, idea, etc.; absurdity.

   the folly of performing without a rehearsal.

   Synonyms:

   lunacy, madness, injudiciousness, indiscretion, foolishness, mistake, rashness, imprudence

3. a costly and foolish undertaking; unwise investment or expenditure.

4. 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.

5. follies, a theatrical revue.

6. Obsolete. wickedness; wantonness.

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folly British  

/ ˈfɒlɪ /

noun

1. the state or quality of being foolish; stupidity; rashness

2. a foolish action, mistake, idea, etc

3. a building in the form of a castle, temple, etc, built to satisfy a fancy or conceit, often of an eccentric kind

4. (plural) theatre an elaborately costumed revue

5. archaic

   1. evil; wickedness

   2. lewdness; wantonness

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Usage

What does folly mean? A folly is a foolish action. Follies can refer to various unwise practices, buildings with a purely ornamental purpose, or cabaret-style theatrical revues featuring lots of beautiful, dancing women.

Other Word Forms

Derived Forms

• superfolly
  noun

Inflected Forms

Nouns

• follies
  plural

Etymology

Origin of folly

First recorded in 1175–1225; Middle English folie, from Old French, derivative of fol, fou “foolish, mad”; equivalent to fool ¹ + -y ³ ( def. )

Explanation

Folly is a noun that means "foolish or crazy behavior." It would be folly to spend all night playing video games when you have a difficult exam the next day. Folly comes from the Old French word folie meaning "madness, stupidity." It can describe the silly or nonsensical things you do, like the folly of trying to rush across town in the middle of a snowstorm. Or it can describe the trait that makes people act that way: the folly of an inexperienced driver who doesn't know you can't speed on snow-covered roads. Can you see the word fool in folly? Not a coincidence.

Example Sentences

See Examples For:

folly follies

Yet if human folly predates the decline of reading, the atrophy of this splendid activity is no less lamentable.

From The Wall Street Journal ● Oct. 7, 2026

Well, sure—although some of us knew folly when we saw it.

From The Wall Street Journal ● Sep. 16, 2026

"Prolonging this parasitic relationship by trying to squeeze the last few drops of expensive oil out of the North Sea is sheer folly," Hopkinson said.

From BBC ● Aug. 4, 2026

Mozeliak probably won’t be around to see the folly of this trade as he will leave this winter and his successor will have to pick up the pieces.

From Los Angeles Times ● Aug. 1, 2026

She still thought the whole thing was folly of the worst kind.

From "Tiger, Tiger" by Lynne Reid Banks

He kept his distance from the collusion follies.

From The Wall Street Journal ● Sep. 29, 2026

In an essay for this year's Proms programme, he admitted that some of the genre's "excesses and follies can seem silly" to a modern eye, while insisting the genre shouldn't be written off.

From BBC ● Apr. 20, 2026

People forget about past follies, either by choice and/or because they’re distracted by the next shiny thing.

From MarketWatch ● Feb. 6, 2026

Without these changes, Californians are probably headed for more fiscal follies in the years ahead.

From Los Angeles Times ● Jan. 27, 2026

"That is why he sent me. To put an end to these follies and bring your son to heel."

From "A Clash of Kings" by George R.R. Martin

Related Words

• absurdity
• craziness
• foolishness
• idiocy
• indiscretion
• lunacy
• madness
• recklessness
• silliness
• stupidity