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Synonyms

wacky

American  
[wak-ee] / ˈwæk i /
Also whacky

adjective

Slang.
wackier, wackiest
  1. odd or irrational; crazy.

    They had some wacky plan for selling more books.


wacky British  
/ ˈwækɪ /

adjective

  1. slang eccentric, erratic, or unpredictable

"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

Other Word Forms

Etymology

Origin of wacky

First recorded in 1935–40; apparently whack (noun, as in out of whack ) + -y 1

Explanation

Something that's wacky is weird or nutty or silly. Your goofy uncle who wears a funny hat and does magic tricks at the dinner table is wacky. Use the adjective wacky when you're talking about someone with a ridiculous sense of humor. Clowns are, by definition, wacky, for example. Most people have at least one wacky relative, and some are lucky enough to have entire wacky families. Wacky comes from the nineteenth century British slang term whacky, which arose from whack, specifically the idea of getting whacked on the head so hard that it turns you 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.

In a May 15 post on X, Weir, 36, declared that he’d had it with the wacky costumes, which have long been a staple of political party conventions but seem particularly popular among do-what-thou-wilt libertarians.

From The Wall Street Journal • May 25, 2026

US director Boots Riley's signature absurdism is all over his latest film "I Love Boosters," which opens in US theaters this week, but the wacky visuals are all in service of an "optimistic" social commentary.

From Barron's • May 20, 2026

Except the BBC went down the wacky route this year, only to fail again.

From BBC • May 17, 2026

Speaking of strange things, here’s my pitch for an “Odd Couple” reboot: Rossdale and Adcock with Fieri as the wacky neighbor.

From Los Angeles Times • Apr. 26, 2026

They spent several quiet minutes wandering around the room, taking in all the wacky games that people used to play.

From "Escape from Mr. Lemoncello's Library" by Chris Grabenstein

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