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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

Derived 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.

Fancy-fy your frozen pizzas with all your favorite condiments, regardless of how wacky the combo may be.

From Salon • Jun. 6, 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

Now it has to add this wacky cart race to the list.

From Los Angeles Times • May 17, 2026

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

From BBC • May 17, 2026

“Mr. Lemoncello is way too wacky to mean exactly what he said.”

From "Mr. Lemoncello's Library Olympics" by Chris Grabenstein

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