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

"It was folly, pure folly," protested Lingard, "and this poor fellow has paid for it."

—Joseph Conrad

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.

5

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

Synonyms of folly

• insanity
• absurdity
• idiocy
• 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

But creativity is born from folly. —Nick Vivarelli, Variety, 8 Jan. 2026

Embedded into the fabric of our nation’s birthplace, Philly cultural institutions are gearing up for high-level deep dives into history, fun, folly, and reflection. —Tribune News Service, Baltimore Sun, 5 Jan. 2026

But that’s the folly of blindly looking ahead. —Glenn Whipp, Los Angeles Times, 2 Jan. 2026

This is a scrapbook of utopian folly, yes, but also an insider’s look at what was, for a time, the wildest workplace on Earth. —Andrew Holter, The Atlantic, 31 Dec. 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