Dictionary.com
Thesaurus.com
Synonyms

crazy

American  
[kray-zee] / ˈkreɪ zi /

adjective

  • crazier,
    comparative
  • craziest
    superlative
  1. mentally deranged; demented; insane.

    Synonyms:
    lunatic, crazed
    Antonyms:
    sane
  2. Informal. unpredictable, nonconforming, or odd.

    All I can say is she's the craziest person I know.

  3. Informal. unusual; bizarre; singular.

    She always wears a crazy hat.

  4. Informal. senseless; nonsensical; totally unsound.

    Surely you don’t plan to invest money in that crazy scheme!

    Synonyms:
    foolhardy, imprudent, foolish
  5. Informal. extremely busy, hectic, chaotic, etc..

    Yesterday was such a crazy day I hardly had time to eat.

  6. Informal. intensely enthusiastic; passionately excited (usually followed by about orfor ).

    Like many kids, he was crazy for baseball and yearned to be a professional ballplayer.

    Antonyms:
    dispassionate, cool
  7. Informal. very enamored or infatuated (usually followed by about orfor ).

    It's obvious he's just crazy about her.

  8. Informal. intensely anxious or eager; impatient.

    I'm crazy to try those new skis.

  9. Informal. very annoyed, frustrated, or bothered.

    It makes me crazy that some kids don't get a fair chance in life.

  10. 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.

  11. Slang. wonderful; excellent; perfect.

    That's crazy, man, crazy.

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

    Synonyms:
    passionate, impassioned, ardent
    Antonyms:
    stable
  13. Archaic. weak, infirm, or sickly.

    Antonyms:
    healthy, strong

adverb

  1. Informal. extremely; madly.

    December is a crazy busy month for us.

    That new clothing store is crazy popular with teenage girls.

noun

  • crazies
    plural
  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.

  3. Informal. the crazies, 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

  1. like crazy,

    1. with great enthusiasm or energy; to an extreme.

      We shopped like crazy and bought all our Christmas gifts in one afternoon.

    2. with great speed or recklessness.

      He drives like crazy once he's out on the highway.

crazy British  
/ ˈkreɪzɪ /

adjective

  1. informal insane

  2. fantastic; strange; ridiculous

    a crazy dream

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

  4. slang very good or excellent

"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

noun

  1. informal a crazy person

"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
crazy More Idioms  

    More idioms and phrases containing crazy


Synonym Usage

See mad.

Other Word Forms

Derived Forms

Inflected Forms

Nouns

Adjectives


Etymology

Origin of crazy

First recorded in 1570–80; craz(e) + -y 1


Explanation

Use the adjective crazy to describe actions that aren't sensible, like the crazy way your brothers run around the house when their favorite team wins a game. Crazy can also mean "insane," though in today's world, it is offensive to apply it to those who struggle with mental illness. Instead, stick with using crazy to describe temporary and more light-hearted situations like being crazy about a new boyfriend or girlfriend or going "football crazy" during the Super Bowl.

Keep Reading on Vocabulary.com

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.

See Examples For:

“And this crazy experiment of Banana Ball has gone some places we never imagined.”

From Los Angeles Times ● Oct. 16, 2026

“Spot VIX sitting around 17.5 doesn’t seem particularly high given the level of market turbulence, which means options protection isn’t crazy expensive right now,” he added.

From MarketWatch ● Oct. 15, 2026

So, it was more aggressive and more on the front foot, and that's why we saw those crazy scenes where it was shot after shot by City.

From BBC ● Oct. 14, 2026

“We have to make sure it’s real people and a real office and a real job and not to go with any crazy who-knows-who,” Tatiana Lichtenstein says.

From The Wall Street Journal ● Oct. 14, 2026

And everyone thought he was crazy for thinking something as small as a butterfly could start a snowball effect capable of wiping out whole cities.

From "Glitch" by Laura Martin

“We leave you alone and you should leave us alone. I mean, primarily those crazies in the West who are already making preparations.”

From Washington Times ● Aug. 18, 2023

It's clear as day who is normal and who the crazies are.

From Salon ● Feb. 8, 2023

I am the only one restraining these crazies.

From Seattle Times ● Jan. 20, 2023

“I almost had Caroline Wren escorted off the property,” she wrote in the message reviewed by The Post, later adding, “I was able to keep the crazies off the stage.”

From Washington Post ● Feb. 26, 2022

The whole way down, we scream and laugh like crazies.

From "I Am Not Your Perfect Mexican Daughter" by Erika L. Sánchez

Well, crazier things have happened than Megyn Kelly switching sides.

From Slate ● May 6, 2026

Driven by Watt's marketing genius, the fledgling company pulled stunt after attention-seeking stunt, each crazier than the last, and they were rarely out of the news.

From BBC ● Mar. 6, 2026

Well, that’s not crazier than what really happened yesterday.

From Salon ● Feb. 22, 2026

This day was really no different than what he normally does… And it just happened to be obviously a way crazier day than normal.

From Los Angeles Times ● Jan. 29, 2026

The worst part was that my mom caught me and now thinks I’m even crazier than before.

From "Sparrow" by Sarah Moon

Babydoll singer Jamie Miller on 'the craziest journey'

From BBC ● Oct. 16, 2026

"This is the craziest thing I've ever heard."

From Barron's ● Oct. 12, 2026

“The ending was the craziest I’ve ever had,” Dorsey Hall of Fame coach Paul Knox said.

From Los Angeles Times ● Aug. 23, 2026

"And this is the lowest, the craziest level it's ever reached."

From Barron's ● Aug. 15, 2026

No Echo speaker that can search the web and answer your craziest questions, like Rachel has.

From "Merci Suárez Changes Gears" by Meg Medina

Random Word

Spin the wheel and learn a new word!

Get a word


Vocabulary.com logo
by dictionary.com

Dictionary.com's Learning Companion

Go beyond just looking up words.
Remember them forever with VocabTrainer.

Start training