Idioms

    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
SYNONYMS FOR mad
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.
Related forms

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.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for mad as a hatter (1 of 2)

MAD

/ (mæd) /

n acronym for 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

British Dictionary definitions for mad as a hatter (2 of 2)

mad

/ (mæd) /

adjective madder or maddest

verb mads, madding or madded

archaic to make or become mad; act or cause to act as if mad
Derived Formsmaddish, adjective

Word Origin for mad

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
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

Medicine definitions for mad as a hatter

mad

[ măd ]

adj.

Angry; resentful.
Suffering from a disorder of the mind; insane.
Affected by rabies; rabid.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Idioms and Phrases with mad as a hatter (1 of 2)

mad as a hatter


Also, mad as a March hare. Crazy, demented, as in She is throwing out all his clothes; she's mad as a hatter. This expression, dating from the early 1800s, alludes to exposure to the chemicals formerly used in making felt hats, which caused tremors and other nervous symptoms. The variant, dating from the 14th century, alludes to the crazy behavior of hares during rutting season, mistakenly thought to be only in March.

Idioms and Phrases with mad as a hatter (2 of 2)

mad


In addition to the idioms beginning with mad

  • mad about
  • mad as a hatter
  • mad as a hornet
  • made for each other
  • made of money
  • made to measure
  • made to order
  • mad rush

also see:

  • crazy (mad) about
  • drive someone crazy (mad)
  • hopping mad
  • like crazy (mad)
  • stark raving mad
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.