[ krey-zee ]
See synonyms for: crazycraziercraziestcrazies on

adjective,cra·zi·er, cra·zi·est.
  1. mentally deranged; demented; insane.

  2. Informal. unpredictable, nonconforming, or odd: All I can say is she's the craziest person I know.

  1. Informal. unusual; bizarre; singular: She always wears a crazy hat.

  2. Informal. senseless; nonsensical; totally unsound: Surely you don’t plan to invest money in that crazy scheme!

  3. Informal. extremely busy, hectic, chaotic, etc.: Yesterday was such a crazy day I hardly had time to eat.

  4. Informal. intensely enthusiastic; passionately excited (usually followed by about or for): Like many kids, he was crazy for baseball and yearned to be a professional ballplayer.

  5. Informal. very enamored or infatuated (usually followed by about or for): It's obvious he's just crazy about her.

  6. Informal. intensely anxious or eager; impatient: I'm crazy to try those new skis.

  7. Informal. very annoyed, frustrated, or bothered: It makes me crazy that some kids don't get a fair chance in life.

  8. Informal. having an unusual, unexpected, or random quality, behavior, result, pattern, etc.: I'm back in Connecticut in a crazy twist of events, living in the same town where I grew up.

  9. Slang. wonderful; excellent; perfect: That's crazy, man, crazy.

  10. Archaic. likely to break or fall to pieces.

  11. Archaic. weak, infirm, or sickly.

  1. Informal. extremely; madly: December is a crazy busy month for us.That new clothing store is crazy popular with teenage girls.

noun,plural cra·zies.
  1. a person who is mentally deranged or insane.

  2. Informal. an unpredictable, nonconforming person; oddball: Next door is a house full of crazies who wear weird clothes and come in at all hours.

  1. the crazies, Informal. a sense of extreme unease, nervousness, or panic; extreme jitters: The crew was starting to get the crazies from being cooped up belowdecks for so long.

Idioms about crazy

  1. like crazy, Informal.

    • with great enthusiasm or energy; to an extreme: We shopped like crazy and bought all our Christmas gifts in one afternoon.

    • with great speed or recklessness: He drives like crazy once he's out on the highway.

Origin of crazy

First recorded in 1570–80; craz(e) + -y1

synonym study For crazy

1. See mad.

Other words for crazy

Opposites for crazy

Other words from crazy

  • cra·zi·ly, adverb
  • cra·zi·ness, noun
  • half-cra·zy, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use crazy in a sentence

  • I must have been crazier than ever, more wildly insane than I had been for the past month, to even think of such a thing.

    The Rise of Roscoe Paine | Joseph C. Lincoln
  • Besides, you can't collect from a crazy man, Connorton; and I'm getting crazier every minute.

  • Gordon stared at them slowly, not quite believing it, even though it was no crazier than anything else during the past few hours.

    Police Your Planet | Lester del Rey
  • Crazier'n you were over the Breed's woman, only he didn't have the nerve.

    The Courage of Marge O'Doone | James Oliver Curwood
  • "Crazier over you every day—and you know it, too, you sly little puss," he answered dreamily.

    The Foolish Virgin | Thomas Dixon

British Dictionary definitions for crazy


/ (ˈkreɪzɪ) /

adjective-zier or -ziest
  1. informal insane

  2. fantastic; strange; ridiculous: a crazy dream

  1. (postpositive; foll by about or over) informal extremely fond (of)

  2. slang very good or excellent

nounplural crazies
  1. informal a crazy person

Derived forms of crazy

  • crazily, adverb
  • craziness, noun

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 Idioms and Phrases with crazy


In addition to the idioms beginning with crazy

  • crazy about, be
  • crazy like a fox

also see:

  • drive someone crazy
  • like crazy

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.