- 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.
- 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.
- Archaic. to make mad.
- 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
SynonymsSee more synonyms on Thesaurus.com
- 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
- mentally deranged; insane
- senseless; foolisha 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; frantica mad rush
- temporarily overpowered by violent reactions, emotions, etcmad with grief
- (of animals)
- unusually ferociousa mad buffalo
- afflicted with rabies
- like mad informal with great energy, enthusiasm, or haste; wildly
- mad as a hatter crazily eccentric
- archaic to make or become mad; act or cause to act as if mad
Word Origin and History for mad as a hatter
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.).
- Angry; resentful.
- Suffering from a disorder of the mind; insane.
- Affected by rabies; rabid.
Idioms and Phrases with mad as a hatter
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.