\ ˈwa-(ˌ)kō How to pronounce wacko (audio) \
variants: or less commonly

Definition of wacko

 (Entry 1 of 2)

: wacky


variants: or less commonly whacko

Definition of wacko (Entry 2 of 2)

: a person who is wacky also : psycho

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Synonyms & Antonyms for wacko

Synonyms: Adjective

balmy, barmy [chiefly British], bats, batty, bedlam, bonkers, brainsick, bughouse [slang], certifiable, crackbrained, cracked, crackers, crackpot, cranky [dialect], crazed, crazy, cuckoo, daffy, daft, demented, deranged, fruity [slang], gaga, haywire, insane, kooky (also kookie), loco [slang], loony (also looney), loony tunes (or looney tunes), lunatic, mad, maniacal (also maniac), mental, meshuga (or meshugge), moonstruck, non compos mentis, nuts, nutty, psycho, psychotic, scatty [chiefly British], screwy, unbalanced, unhinged, unsound, wacky (also whacky), wud [chiefly Scottish]

Synonyms: Noun

bug, crackbrain, crazy, fool, fruitcake, head case, loon, loony, lunatic, maniac, nut, nutcase, nutter [British slang], psycho, psychopath, sickie, sicko

Antonyms: Adjective

balanced, compos mentis, sane, sound, uncrazy

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Examples of wacko in a Sentence


She's nice but her sister's a real wacko. some wacko has been sending the actress increasingly disturbing letters

Recent Examples on the Web: Adjective

But the downside of the mockery is glibness; if only the racists and terrorists of the world came as clearly labeled as this flagrantly wacko crew. Joe Morgenstern, WSJ, "‘BlacKkKlansman’ Review: Running on Fury," 9 Aug. 2018 Ashley also seems to think that whoever killed the girls did it for popularity, a wacko theory that gets put to the test when she and John are collectively shunned at the house party. Emma Dibdin, Harper's BAZAAR, "Sharp Objects Episode 6: Camille Is in Deep Trouble," 13 Aug. 2018 Just a few years ago, McCain called Paul and fellow Sen. Ted Cruz, R-Texas, ‘‘wacko birds’’ for their filibuster blocking then-CIA nominee John Brennan. Lisa Mascaro, BostonGlobe.com, "McCain is still up for a fight, even as he battles a deadly illness," 12 May 2018 Berry reminded Cruz supporters that Arizona Sen. John McCain had called Cruz a wacko bird and Cruz had voted in opposition of Senate Majority Leader Mitch McConnell more than 80 times. Jeremy Wallace, Houston Chronicle, "Beto O'Rourke says Pelosi, Schumer don't understand Texas," 6 Apr. 2018 Bolton is a more serious and well-disciplined version of the chaotic Steve Bannon, or the president’s first national security advisor, the wacko Mike Flynn. Trudy Rubin, Philly.com, "What H.R. McMaster's exit and John Bolton's arrival mean for the next three dangerous months | Trudy Rubin," 23 Mar. 2018 That edge allowed him to go wacko on Erin Andrews in a post-game interview, give the choke sign to the Niners after that game, and made him go batcrap on Darrell Bevell on the sidelines of a big game. Peter King, SI.com, "Free Agency Free-For-All: Thoughts On All The Deals Done Before The NFL Year Opens," 14 Mar. 2018 There is none of, say, Stone’s wacko conspiracy theorizing from JFK. Lincoln Michel, GQ, "The Untold History of the United States Is the Documentary Every American Should Watch on Netflix," 26 Aug. 2017 The Trip to Spain (August 11) Having already toured northern England and Italy, Steve Coogan and Rob Brydon—playing wacko variations of themselves—now take to Spain for the third installment in Michael Winterbottom's British comedy series. Nick Schager, Esquire, "11 Movies Worth the Haul to the Multiplex in August 2017," 27 July 2017

Recent Examples on the Web: Noun

Now, all those wackos who’ve been writing to me with their problems can write to her. Rick Kogan, chicagotribune.com, "On the 100th birthday of Ann Landers, a play, a typewriter and a lot of memories," 28 June 2018 At the very least, in a game that has known a lot of eccentrics LaVar has put himself in the running for the greatest wacko. Mark Heisler, Orange County Register, "Heisler: Lakers pray for shot at Lonzo Ball (and the father that comes with him)," 12 May 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'wacko.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of wacko


1965, in the meaning defined above


1936, in the meaning defined above

History and Etymology for wacko


by alteration

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Statistics for wacko

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Time Traveler for wacko

The first known use of wacko was in 1936

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More Definitions for wacko



English Language Learners Definition of wacko

US, informal : a person who is crazy or very strange and unusual

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Comments on wacko

What made you want to look up wacko? Please tell us where you read or heard it (including the quote, if possible).


to complain fretfully

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