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foolish

American  
[foo-lish] / ˈfu lɪʃ /

adjective

  1. resulting from or showing a lack of sense; ill-considered: unwise.

    a foolish action;

    a foolish speech.

    Synonyms:
    thoughtless, imprudent, preposterous, nonsensical, absurd, ridiculous, unintelligent, senseless, brainless, witless, stupid
  2. lacking forethought or caution.

    Synonyms:
    thoughtless, imprudent, incautious, heedless, half-baked, foolhardy, reckless, rash, impetuous
  3. trifling, insignificant, or paltry.

    Synonyms:
    picayune, trivial

foolish British  
/ ˈfuːlɪʃ /

adjective

  1. unwise; silly

  2. resulting from folly or stupidity

  3. ridiculous or absurd; not worthy of consideration

  4. weak-minded; simple

  5. an archaic word for insignificant

"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

foolish Idioms  

Usage

What are other ways to say foolish? A foolish action is one that shows a lack of sense or is ill-considered. How is foolish different from fatuous, silly, inane, stupid, and asinine? Find out on Thesaurus.com. 

Other Word Forms

  • foolishly adverb
  • foolishness noun
  • overfoolish adjective
  • overfoolishly adverb
  • quasi-foolish adjective
  • quasi-foolishly adverb
  • unfoolish adjective
  • unfoolishly adverb

Etymology

Origin of foolish

First recorded in 1250–1300; from Middle English folish, foolish; fool 1, -ish 1

Explanation

Foolish people are silly or senseless, and when you do something foolish, it's clearly unwise or irrational. Sitting on the hood of a car while your friend is driving is a foolish thing to do. Things that show a lack of judgment are foolish, like cheating on a test or running into the street after a basketball. Foolish decisions at work can cost you your job, and foolish comments can hurt people's feelings. Foolish is a 14th century word that comes from fool, a person who's unwise. The Latin root, follis, means "bellows" or "leather bag." The "silly person" meaning comes from the figurative idea of a "windbag."

Keep Reading on Vocabulary.com

Vocabulary lists containing foolish

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Locals praised the sender for making amends, with one writing: "A lovely, kind gesture to make up for foolish actions from years ago."

From BBC • Mar. 24, 2026

Go through the account activity together, framing it as a routine check rather than accusing him of being foolish or incompetent.

From MarketWatch • Mar. 23, 2026

Hatosy’s Titus is the Danforths’ disappointing fail son and the actor keeps his face in a delightfully foolish little pout.

From Los Angeles Times • Mar. 19, 2026

It would be foolish to make confident predictions about what will happen in this war, except to say that nearly all potential outcomes are likely to create much bigger problems down the road.

From Salon • Mar. 8, 2026

Of course a struggling animal would attract predators—she had been foolish to put off checking the snares.

From "A Girl Named Disaster" by Nancy Farmer