Try Our Apps


Avoid these words. Seriously.


[mad] /mæd/
adjective, madder, maddest.
mentally disturbed; deranged; insane; demented.
enraged; greatly provoked or irritated; angry.
  1. abnormally furious; ferocious:
    a mad bull.
  2. affected with rabies; rabid:
    a mad dog.
extremely foolish or unwise; imprudent; irrational:
a mad scheme to invade France.
wildly excited or confused; frantic:
mad haste.
overcome by desire, eagerness, enthusiasm, etc.; excessively or uncontrollably fond; infatuated:
He's mad about the opera.
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.
an angry or ill-tempered period, mood, or spell:
The last time he had a mad on, it lasted for days.
verb (used with object), madded, madding.
Archaic. to make mad.
verb (used without object), madded, madding.
Archaic. to be, become, or act mad.
like mad, Informal. with great haste, impulsiveness, energy, or enthusiasm:
She ran like mad to catch the bus.
mad as a hatter, completely insane.
Origin of mad
before 900; Middle English mad (adj.), madden (intransitive v., derivative of the adj.); Old English gemǣd(e)d, past participle of *gemǣdan to make mad, akin to gemād mad, foolish; cognate with Old Saxon gemēd, Old High German gimeit foolish
Related forms
half-mad, adjective
half-madly, adverb
half-madness, noun
quasi-mad, adjective
quasi-madly, adverb
unmad, adjective
unmadded, adjective
1. lunatic, maniacal, crazed, crazy. 2. furious, exasperated, raging, wrathful, irate. 4. ill-advised; unsafe, dangerous, perilous. 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. 5. frenzied.
4. sensible, practical; sound, safe.
Usage note
Mad meaning “enraged, angry” has been used since 1300, 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.


[mad] /mæd/


1. Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
Cite This Source
Examples from the Web for mad
Contemporary Examples
Historical Examples
  • He was so handsome and so gifted, and there were women who were mad about him.

    K Mary Roberts Rinehart
  • Heaven knows what mad instinct was at the back of his brain.

    The Bacillus of Beauty Harriet Stark
  • But wasn't it awfully risky to keep making him mad like that?

    The Trail Book Mary Austin
  • Were they all mad—was he not standing with one foot in the penitentiary?

    Thoroughbreds W. A. Fraser
  • If it mad not been for Ben, nothing more would have been done or said about, the matter.

    Biographical Stories Nathaniel Hawthorne
British Dictionary definitions for mad


adjective madder, maddest
mentally deranged; insane
senseless; foolish: a mad idea
(often foll by at) (informal) angry; resentful
foll by about, on, or over; often postpositive. wildly enthusiastic (about) or fond (of): mad about football, football-mad
extremely excited or confused; frantic: a mad rush
temporarily overpowered by violent reactions, emotions, etc: mad with grief
(of animals)
  1. unusually ferocious: a mad buffalo
  2. afflicted with rabies
(informal) like mad, with great energy, enthusiasm, or haste; wildly
mad as a hatter, crazily eccentric
verb mads, madding, madded
(archaic) to make or become mad; act or cause to act as if mad
Derived Forms
maddish, adjective
Word Origin
Old English gemǣded, past participle of gemǣdan to render insane; related to gemād insane, and to Old High German gimeit silly, crazy, Old Norse meitha to hurt, damage


noun acronym (US)
mutual assured destruction: a theory of nuclear deterrence whereby each side in a conflict has the capacity to destroy the other in retaliation for a nuclear attack
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
Cite This Source
Word Origin and History for mad

late 13c., from Old English gemædde (plural) "out of one's mind" (usually implying also violent excitement), also "foolish, extremely stupid," earlier gemæded "rendered insane," past participle of a lost verb *gemædan "to make insane or foolish," from Proto-Germanic *ga-maid-jan, demonstrative form of *ga-maid-az "changed (for the worse), abnormal" (cf. Old Saxon gimed "foolish," Old High German gimeit "foolish, vain, boastful," Gothic gamaiþs "crippled, wounded," Old Norse meiða "to hurt, maim"), from intensive prefix *ga- + PIE *moito-, past participle of root *mei- "to change" (cf. Latin mutare "to change," mutuus "done in exchange," migrare "to change one's place of residence;" see mutable).

Emerged in Middle English to replace the more usual Old English word, wod (see wood (adj.)). Sense of "beside oneself with excitement or enthusiasm" is from early 14c. Meaning "beside oneself with anger" is attested from early 14c., but deplored by Rev. John Witherspoon (1781) as an Americanism. It now competes in American English with angry for this sense. Of animals, "affected with rabies," from late 13c. Phrase mad as a March hare is attested from 1520s, via notion of breeding season; mad as a hatter is from 1829 as "demented," 1837 as "enraged," according to a modern theory supposedly from erratic behavior caused by prolonged exposure to poison mercuric nitrate, used in making felt hats. For mad as a wet hen see hen. Mad money is attested from 1922; mad scientist is from 1891.


late 14c., from mad (adj.).

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
mad in Medicine

mad (mād)

  1. Angry; resentful.

  2. Suffering from a disorder of the mind; insane.

  3. Affected by rabies; rabid.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
Slang definitions & phrases for mad



  1. Angry (1400s+)
  2. Excellent; exciting; crazy (1950s+ Bop & cool talk)

Related Terms

like mad

The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D.
Copyright (C) 2007 by HarperCollins Publishers.
Cite This Source
Idioms and Phrases with mad
The American Heritage® Idioms Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source

Word of the Day

Nearby words for mad

Difficulty index for mad

Most English speakers likely know this word

Word Value for mad

Scrabble Words With Friends