folly

noun

fol·​ly ˈfä-lē 

plural follies

1

: lack of good sense or normal prudence and foresight

his folly in thinking he could not be caught

2

a

: criminally or tragically foolish actions or conduct

b

obsolete : evil, wickedness

especially : lewd behavior

3

: a foolish act or idea

The prank was a youthful folly.

4

: an excessively costly or unprofitable undertaking

Paying so much for that land was folly, since it was all rocks and scrub trees.

5

: an often extravagant picturesque building erected to suit a fanciful taste

Synonyms

• absurdity
• asininity
• bêtise
• fatuity
• foolery
• foppery
• idiocy
• imbecility
• inanity
• insanity
• lunacy
• stupidity

Examples of folly in a Sentence

the folly of driving fast on steep, winding roads

his folly in thinking that he would not be noticed

The folly of such an action should be apparent to everyone.

the follies of the modern world

the famous Ziegfeld Follies of the 1920s

Recent Examples on the Web

See above to see the folly of the inflation definition. —John Tamny, Forbes, 2 Mar. 2025

Events have called them to lead us through a high tide of reckless folly. —Kevin Rennie, Hartford Courant, 1 Mar. 2025

The 10-episode series (now streaming) follows the follies of the fictitious NBA team, the Los Angeles Waves, after Isla Gordon (Hudson) steps in to run it with her brothers (Drew Tarver and Scott MacArthur) when another (Justin Theroux) checks into rehab. —Erin Jensen, USA TODAY, 1 Mar. 2025

Paper money can see its value evaporate if fiscal folly prevails. —Yun Li, CNBC, 22 Feb. 2025

Word History

Etymology

Middle English folie, from Anglo-French, from fol fool

First Known Use

13th century, in the meaning defined at sense 1

Rhymes for folly

• colley
• collie
• dolly
• golly
• holly
• jolley
• jolly
• lolly
• mollie
• molly
• ollie
• polly

Kids Definition

folly

noun

fol·​ly ˈfäl-ē 

plural follies

1

: lack of good sense or judgment

2

: foolish behavior

3

: a foolish act or idea