idiocy

American  

[id-ee-uh-see] / ˈɪd i ə si /

noun

plural

idiocies

1. 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

2. 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.

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idiocy British  

/ ˈɪdɪəsɪ /

noun

1. (not in technical usage) severe mental retardation

2. foolishness or senselessness; stupidity

3. a foolish act or remark

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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”; idiot, -cy

Example Sentences

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

Utter asininity is the bread and butter of “The Naked Gun,” and the movie milks cop idiocy for all its worth.

From Salon • Aug. 1, 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

In time they grew sick of my idiocy.

From "Woodsong" by Gary Paulsen

Related Words

• insanity
• lunacy
• madness