mad
adjective
mentally disturbed; deranged; insane; demented.
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mad
1 American
[mad]
/ mæd /
adjective
comparative
madder,superlative
maddest-
mentally disturbed; deranged; insane; demented.
-
enraged; greatly provoked or irritated; angry.
-
(of animals)
-
abnormally furious; ferocious.
a mad bull.
-
affected with rabies; rabid.
a mad dog.
-
-
extremely foolish or unwise; imprudent; irrational.
a mad scheme to invade France.
- Synonyms:
- perilous, dangerous, unsafe, ill-advised
-
wildly excited or confused; frantic.
mad haste.
- Synonyms:
- frenzied
-
overcome by desire, eagerness, enthusiasm, etc.; excessively or uncontrollably fond; infatuated.
He's mad about the opera.
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wildly lively and merry; enjoyably hilarious.
to have a mad time at the Mardi Gras.
-
(of wind, storms, etc.) furious in violence.
A mad gale swept across the channel.
-
Slang. much or many.
Mad props for getting this organization off the ground.
adverb
verb (used with object)
madded,
madding
verb (used without object)
madded,
madding
idioms
-
like mad, with great haste, impulsiveness, energy, or enthusiasm.
She ran like mad to catch the bus.
-
have a mad on, to be angry for a period of time; be in a bad mood.
The last time he had a mad on, it lasted for days.
-
mad as a hatter, completely insane.
MAD
2
American
[mad]
/ mæd /
noun
mad.
3
American
abbreviation
mad
1
British
/ mæd /
adjective
-
mentally deranged; insane
-
senseless; foolish
a mad idea
-
informal (often foll by at) angry; resentful
-
wildly enthusiastic (about) or fond (of)
mad about football
football-mad
-
extremely excited or confused; frantic
a mad rush
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temporarily overpowered by violent reactions, emotions, etc
mad with grief
-
-
unusually ferocious
a mad buffalo
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afflicted with rabies
-
-
informal with great energy, enthusiasm, or haste; wildly
-
crazily eccentric
verb
MAD
2
British
/ mæd /
acronym
mad
More Idioms
Usage
Mad meaning “enraged, angry” has been used since 1400, and this sense is a very common one. Because some teachers and usage critics insist that the only correct meaning of mad is “mentally disturbed, insane,” mad is often replaced by angry in formal contexts: The president is angry at Congress for overriding his veto.
Related Words
Mad, crazy, insane are used to characterize wildly impractical or foolish ideas, actions, etc. Mad suggests senselessness and excess: The scheme of buying the bridge was absolutely mad. In informal usage, crazy suggests recklessness and impracticality: a crazy young couple. Insane is used with some opprobrium to express unsoundness and possible harmfulness: The new traffic system is simply insane.
Other Word Forms
Etymology
Origin of mad
First recorded before 900; Middle English mad (adjective), madden (intransitive verb, derivative of the adjective); Old English gemǣd “made mad,” past participle of gemǣdan (unrecorded) “to make mad,” akin to gemād “mad, foolish”; cognate with Old Saxon gemēd, Old High German gimeit “foolish”
Explanation
If you're mad about something, you've lost your temper. If you've gone mad, you've lost your mind. Just like it's more common to be angry than to be insane, you're more likely to use mad to describe someone who's ticked off than to describe someone who has serious mental problems. If you say you're “mad about” something, you're saying you like it so much it distracts you.
Vocabulary lists containing mad
In the Mood? 100 Words to Describe Emotions
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Hooked on a Feeling, List 1
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
"The Tell-Tale Heart" and "The Raven"
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
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.
I remember being really mad at my parents in 1984, that they had chosen to leave L.A. for vacation right as the Games were starting, instead of attending.
From Los Angeles Times • May 7, 2026
Perhaps the best part was Michael Che’s complete bafflement as to who these women are and why they’re mad at each other.
From Los Angeles Times • May 3, 2026
"I'm mad about the price, but I'm even madder about why it's so high," the 28-year-old told AFP.
From Barron's • May 2, 2026
But five people living with the condition spoke to the BBC about their ordeals, which left them feeling like they were going mad or like monsters.
From BBC • Apr. 29, 2026
I had heard it used in school about mad animals, but it startled me, too.
From "Black Star, Bright Dawn" by Scott O'Dell
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.
