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Synonyms

wacko

American  
[wak-oh] / ˈwæk oʊ /
Also whacko

noun

plural

wackos
  1. Also an eccentric, strange, or odd person.


adjective

  1. wacky.

wacko British  
/ ˈwækəʊ /

adjective

  1. mad or eccentric

"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. a mad or eccentric 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

Etymology

Origin of wacko

First recorded in 1970–75, wacky, -o

Explanation

Describing someone as a wacko is a derogatory way to say they're quirky or eccentric. It may be tempting to call the neighbor who walks his pet peacock on a leash a wacko, but it wouldn't be very nice. You'll often hear someone use the word wacko as a way of dismissing people whose opinions or lifestyle they don't understand or agree with. If your cranky uncle complains about the wackos in town, then he's probably talking about a group of people he doesn't like very well. This informal noun first appeared around 1938, from wacky.

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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.

Do you look back at the risks you took, with unusual buildings designed by foreign architects with no experience in China, as wacko now?

From The Wall Street Journal • Apr. 10, 2026

In April, he was expelled from the House of Commons for calling the prime minister a "wacko".

From BBC • Jan. 8, 2025

People think I’m a little wacko, but I believe plants are like people.

From Los Angeles Times • Feb. 8, 2023

"We obviously can't be surprised if we lose. We're not that wacko," he told the outlet.

From Salon • Nov. 18, 2022

“Listen, man, you can’t go around sinkin’ other people’s boats just because you get some wacko idea in your head,” Dusty told him.

From "Flush" by Carl Hiaasen