crazy
Americanadjective
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mentally deranged; demented; insane.
- Antonyms:
- sane
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Informal. unpredictable, nonconforming, or odd.
All I can say is she's the craziest person I know.
-
Informal. unusual; bizarre; singular.
She always wears a crazy hat.
-
Informal. senseless; nonsensical; totally unsound.
Surely you don’t plan to invest money in that crazy scheme!
-
Informal. extremely busy, hectic, chaotic, etc..
Yesterday was such a crazy day I hardly had time to eat.
-
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
-
Informal. very enamored or infatuated (usually followed by about orfor ).
It's obvious he's just crazy about her.
-
Informal. intensely anxious or eager; impatient.
I'm crazy to try those new skis.
-
Informal. very annoyed, frustrated, or bothered.
It makes me crazy that some kids don't get a fair chance in life.
-
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.
-
Slang. wonderful; excellent; perfect.
That's crazy, man, crazy.
-
Archaic. likely to break or fall to pieces.
- Synonyms:
- passionate, impassioned, ardent
- Antonyms:
- stable
-
Archaic. weak, infirm, or sickly.
adverb
noun
-
a person who is mentally deranged or insane.
-
Informal. an unpredictable, nonconforming person; oddball.
Next door is a house full of crazies who wear weird clothes and come in at all hours.
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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
adjective
-
informal insane
-
fantastic; strange; ridiculous
a crazy dream
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informal (postpositive; foll by about or over) extremely fond (of)
-
slang very good or excellent
noun
Related Words
See mad.
Other Word Forms
Etymology
Origin of crazy
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.
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.
The problem: “Like Crazy Eddie, for those that remember him, the fees are ‘insane,’” says institutional investor Michael Weinberg, an adjunct professor at Columbia Business School.
From Barron's • May 21, 2026
She stepped away from the industry after Robin Williams, her co-lead in the short-lived but promising series, “The Crazy Ones,” died in 2014.
From Salon • Mar. 26, 2026
“Do you really believe I’d give you an answer? Crazy question,” he said.
From Los Angeles Times • Mar. 23, 2026
Wimbledon were known for their various antics during the Crazy Gang era of the 1980s, finding all sorts of ways to try to intimidate more vaunted opposition.
From BBC • Nov. 10, 2025
“His name was Lone Bear. They’d been friends since boyhood. They were separated in the fighting. After it was over, Crazy Horse was looking around for him.”
From "In the Footsteps of Crazy Horse" by Joseph Marshall III
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
