idiocy
Americannoun
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utterly senseless or foolish behavior; a stupid or foolish act, statement, etc..
All this talk of zombies coming to attack us is pure idiocy.
- Synonyms:
- folly, inanity, foolishness
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Psychology. (no longer in technical use; considered offensive) an intellectual disability, previously classified in a now obsolete rubric of developmental disorders as having a mental age of less than three years old and an intelligence quotient under 25.
noun
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(not in technical usage) severe mental retardation
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foolishness or senselessness; stupidity
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a foolish act or remark
Other Word Forms
Etymology
Origin of idiocy
First recorded in 1520–30; from Medieval Latin idiotia “imbecility,” from Hellenistic Greek idiōteía “uncouthness, ignorance,” Greek “state of being a private person”; see origin at idiot, -cy
Explanation
Idiocy is extreme stupidity. If you skied down a dangerous slope with little experience and no helmet, your friends would be right to comment on your idiocy. When someone behaves in a foolish way, showing no evidence that they've thought about their actions, you can call it idiocy. You could scold your little brother, "Your idiocy in the bouncy house made it impossible for anyone else to have fun at the party," or criticize the idiocy of your governor's decision to refuse federal funds for school lunches. The noun idiot came before idiocy, and both words originally had psychiatric meanings that are now obsolete.
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.
Denford’s mission is to interrupt the spinning vortex of negativity in which the world is caught by redirecting our energy instead of contributing one more fiery rebuttal to sexist idiocy.
From Salon • Apr. 5, 2026
A few days later I saw a friend who knows his foreign affairs and he said, “Do you believe the idiocy of this guy?”
From The Wall Street Journal • Oct. 9, 2025
She must navigate the idiocy of her high school peers while solving a metaphysical murder mystery.
From Los Angeles Times • Aug. 6, 2025
I call on George Santos to engineer a crypto fleece or a phishing operation or really any scheme worthy of his singular, astonishing idiocy.
From Slate • Nov. 16, 2023
And now, because of my idiocy, she has tracked me right to my family.
From "Legend" by Marie Lu
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
