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

---

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

---

noun

1. informal a crazy person

crazy More Idioms  

More idioms and phrases containing crazy

• drive someone crazy
• like crazy

---

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

"When we are ever in the lead it feels like a crazy amount of time on it," said Leeds boss Daniel Farke afterwards.

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

“Because we sat down and said, ‘We’ve just had the most crazy experience.’”

From "The Big Short" by Michael Lewis

Related Words

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