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maniac

American  
[mey-nee-ak] / ˈmeɪ niˌæk /

noun

  1. a raving or violently insane person; lunatic.

  2. any intemperate or overly zealous or enthusiastic person.

    a maniac when it comes to details.


adjective

  1. maniacal.

maniac British  
/ ˈmeɪnɪˌæk /

noun

  1. a wild disorderly person

  2. a person who has a great craving or enthusiasm for something

    a football maniac

  3. obsolete psychiatry a person afflicted with mania

"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

Etymology

Origin of maniac

First recorded in 1595–1605, maniac is from the Medieval Latin word maniacus of, pertaining to madness. See mania, -ac

Explanation

A maniac is a crazy person. Screaming like a maniac is never a good way to get your point across. Long ago, the word maniac was an official psychiatric term that meant "a patient suffering from mania," or manic disorder, involving a euphoric mood and extreme energy. Maniac isn't used in a clinical way anymore, but only informally to mean "lunatic." You might describe yourself running around the house like a maniac looking for your car keys, or dismiss your sports-obsessed brother as "a football maniac." The Greek root is mania, or "madness."

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Vocabulary lists containing maniac

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.

Walking and typing is dangerous, but walking and talking like a maniac into my own recorder is merely antisocial.

From Slate • May 24, 2026

The “Saturday Night Live” head writer made the most of his time on two legs, playing Secretary of Defense Pete Hegseth as a swaggering, pro wrestling-esque maniac.

From Salon • Dec. 7, 2025

In a subsequent interview with The Times, Pilatus admitted the claims were true.”We are true singers, but that maniac Frank Farian would never allow us to express ourselves,” he said.

From Los Angeles Times • Oct. 27, 2023

“And I’m not some crazed maniac set out to destroy this nation.”

From Seattle Times • Oct. 6, 2023

Herky hung upside down and laughed like a maniac, and cried, “Bad bird! Bad bird!”

From "The Hot Zone" by Richard Preston

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