Mad Definition

măd

madded, madder, maddest, madding, mads

adjective

madder, maddest

Mentally ill; insane.

Webster's New World

Wildly excited or disorderly; frenzied; frantic.

Mad with fear.

Webster's New World

Characteristic of mental derangement.

Mad laughter.

American Heritage

Angry or provoked.

Webster's New World

Showing or resulting from lack of reason; foolish and rash; unwise.

A mad scheme.

Webster's New World

Synonyms:

Antonyms:

verb

madded, madding, mads

To make or become mad; madden.

American Heritage

To madden.

Webster's New World

(now colloquial US) To madden, to anger, to frustrate.

Wiktionary

adverb

Extremely; very.

This place is mad cool.

American Heritage

(slang, New England, New York and UK, dialect) Intensifier; to a large degree; extremely; exceedingly; very; unbelievably.

He was driving mad slow.

It's mad hot today.

He seems mad keen on her.

Wiktionary

abbreviation

Mutually assured destruction.

American Heritage

noun

An angry or sullen mood or fit.

Webster's New World

The theory that the possession of equally devastating nuclear weapons by superpowers will deter each from attacking another or its allies.

Webster's New World

Synonyms:

idiom

like mad

Wildly; impetuously:
drove like mad.
To an intense degree or great extent:
worked like mad; snowing like mad.

American Heritage

mad as a hatter

Crazy; mentally deranged.

American Heritage

have a mad on

to be angry

Webster's New World

mad as a hatter

completely crazy

Webster's New World

Other Word Forms of Mad

Adjective

Base Form:

mad

Comparative:

madder

Superlative:

maddest

Idioms, Phrasal Verbs Related to Mad

Origin of Mad

Middle English medd, madd, from Old English gemÇ£d (“enraged"), from gemād (“silly, mad"), from Proto-Germanic *maidaz (compare Old High German gimeit (“foolish, crazy"), Gothic gamaiþs (gamaiþs, “crippled")), past participle of *maidijanÄ… (“to cripple, injure"), from Proto-Indo-European *mei (“to change") (compare Old Irish máel (“bald, dull"), Old Lithuanian ap-maitinti (“to wound"), Sanskrit [script?] (méthati, “he hurts, comes to blows")).

From Wiktionary
Middle English mentally deranged, rabid, angry from Old English gemǣdde past participle of gemǣdan to derange mentally, madden from gemād mentally deranged mei-¹ in Indo-European roots

From American Heritage Dictionary of the English Language, 5th Edition