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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

  • wackily adverb
  • wackiness noun

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.

With his latest, “Kontinental ’25,” Jude — who also put out a coarsely wacky version of “Dracula” last year — shifts away from clownishness and toward a sterner register of concern for society.

From Los Angeles Times • Apr. 3, 2026

Those sentiments echoed the words of previous stars of “The Bachelorette,” a spin-off of the network’s “The Bachelor” franchise centered on rose-colored romance, wacky contests, fantasy suites, exotic locations and over-the-top drama.

From Los Angeles Times • Mar. 24, 2026

However, their wacky little world is no longer what it once was.

From Salon • Feb. 26, 2026

Like many wild and wacky ideas, it all started down at the pub.

From BBC • Feb. 20, 2026

I could maybe find some mad scientist to cryogenically freeze me, but chances are I’d die in the middle of that wacky experiment.

From "They Both Die at the End" by Adam Silvera