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Synonyms

stupid

American  
[stoo-pid, styoo‑] / ˈstu pɪd, ˈstyu‑ /

adjective

stupider, stupidest
  1. lacking ordinary quickness and keenness of mind; slow-witted.

  2. characterized by or proceeding from mental dullness; foolish; senseless.

    Sorry for asking a stupid question, but why is the answer four instead of five?

  3. tediously boring, especially due to lack of meaning or sense; inane; pointless.

    He wished he'd never come to such a stupid party.

  4. annoying or irritating; troublesome.

    Turn off that stupid radio.

  5. in a state of stupor; stupefied.

    After a twelve-hour work day, she was stupid from fatigue.

  6. Slang. excellent; terrific.


noun

  1. Informal. a stupid person.

stupid British  
/ ˈstjuːpɪd /

adjective

  1. lacking in common sense, perception, or normal intelligence

  2. (usually postpositive) stunned, dazed, or stupefied

    stupid from lack of sleep

  3. having dull mental responses; slow-witted

  4. trivial, silly, or frivolous

"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

noun

  1. informal a stupid person

"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

Usage

What are other ways to say stupid? The adjective stupid describes things characterized or proceeding from mental dullness. Do you know when to use stupid, fatuous, silly, inane, foolish, and asinine? Find out on Thesaurus.com.

Commonly Confused

Stupid, ignorant, and unintelligent are all used to refer to people or things that seem to show a lack of mental resources. Stupid is the most general and most insulting term, and can describe someone lacking in intelligence, wisdom, prudence, or mental quickness. Unintelligent refers to people or things that are lacking in capacity for learning, reasoning, or understanding. Ignorant, by contrast, generally means lacking in knowledge (not necessarily lacking in intelligence).

Related Words

See dull.

Other Word Forms

  • stupidly adverb
  • stupidness noun
  • unstupid adjective
  • unstupidly adverb
  • unstupidness noun

Etymology

Origin of stupid

First recorded in 1535–45; from Latin stupidus, equivalent to stup(ēre) “to be numb, to be stunned” + -idus -id 4 ( def. )

Explanation

A stupid person doesn’t have much intelligence or imagination, and they go through life making decisions that seem to lack all common sense. If you’ve got a brain but you don’t use it, you might be a bit stupid. The word comes from a Latin adjective that means “amazed or stunned,” and stupid people are stunned by everything because their minds are numb. You can make a stupid mistake when you’re not thinking, and you can call someone stupid if you’re feeling cruel, like “Hey, Stupid.” Zombies are stupid because their brains are dead. If that makes sense to you, then you’re not stupid, and you’re also not a zombie. Well done!

Keep Reading on Vocabulary.com

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.

“They’re stupid people, they know it, their families know it, and everyone else knows it, too!” he wrote.

From Salon • Apr. 9, 2026

Yet in a post on X, Sam Altman wrote: “I don’t expect them to go any easier on us, am sure I’ll do my part to help enable that with occasional stupid decisions.”

From MarketWatch • Apr. 3, 2026

"For me, the worry is probably no-one else is stupid enough to do that, or driven enough," she says.

From BBC • Mar. 28, 2026

“Right now, I’m looking for a lawyer. ... I can’t believe I’m getting sued for telling a joke. What kind of stupid world do we live in?” he added.

From Los Angeles Times • Mar. 27, 2026

I say with a rush of affection for that stupid car.

From "The Tenth Mistake of Hank Hooperman" by Gennifer Choldenko