crazy

American  

[krey-zee] / ˈkreɪ zi /

adjective

crazier, craziest

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

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adverb

1. Informal. extremely; madly.

   December is a crazy busy month for us.

   That new clothing store is crazy popular with teenage girls.

noun

plural

crazies

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

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noun

1. informal a crazy person

crazy More Idioms  

More idioms and phrases containing crazy

• drive someone crazy
• like crazy

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Related Words

See mad.

Other Word Forms

• crazily adverb
• craziness noun
• half-crazy adjective

Etymology

Origin of crazy

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

Example Sentences

They were put through a range of emotions in a crazy, breathtaking quarter-final at West Ham.

From BBC • Apr. 5, 2026

Any academy coaches entering the crazy world of club management will also grab the importance of the club's alignment, and how well every part works together.

From BBC • Apr. 3, 2026

Lindsay Nead: I’ve heard people say, “Oh, I fully maxed my credit card to get clothing for the show” or “I’m in crazy debt, I left my job.”

From The Wall Street Journal • Apr. 3, 2026

“It’s been a really crazy, amazing five years of real estate,” she reflects.

From MarketWatch • Apr. 3, 2026

“The whole gluten-free thing. The restaurant industry just made it up so they could put another more expensive option on their menu. It’s crazy how many idiots buy into it.”

From "Red Flags and Butterflies" by Sheryl Azzam

Related Words

• absurd
• bizarre
• foolish
• goofy
• insane
• irresponsible
• ludicrous
• odd
• outrageous
• preposterous
• ridiculous
• silly
• strange
• weird