Cambridge Dictionaries online Cambridge Dictionaries online

The most popular online dictionary and thesaurus for learners of English

English definition of “mad”

mad

adjective uk   /mæd/ (madder or maddest) us  

mad adjective (MENTALLY ILL)

B1 mentally ill, or unable to behave in a reasonable way: I think I must be going mad. Do I look like some mad old woman in this hat?

mad adjective (SILLY)

B1 mainly UK informal (US usually crazy) extremely silly or stupid: [+ to infinitive] You're mad to walk home alone at this time of night. He must be mad spending all that money on a coat. Some of the things she does are completely mad.
See also

mad adjective (ANGRY)

A2 [after verb] informal very angry or annoyed: He's always complaining and it makes me so mad.mainly US Are you still mad at me?mainly UK Kerry got really mad with Richard for not doing the washing up. Bill's untidiness drives me mad.

mad adjective (HURRYING)

[before noun] hurrying or excited and not having time to think or plan: We made a mad dash for the train. I was in a mad panic/rush trying to get everything ready.

mad adjective (ENTHUSIASTIC)

be mad about sb/sth B1 informal to love someone or something: He's the first real boyfriend she's had and she's mad about him. He's mad about football. be mad for sb/sth UK informal to want someone or something very much, or to be very interested in someone or something: Everyone's mad for him and I just don't see the attraction.
(Definition of mad adjective from the Cambridge Advanced Learners Dictionary & Thesaurus © Cambridge University Press)
What is the pronunciation of mad?
Add Cambridge dictionaries to your browser to your website

Definitions of “mad” in other dictionaries

Word of the Day

monster

any imaginary frightening creature, especially one that is large and strange

Word of the Day

What’s that lovely smell?

by Kate Woodford,
October 29, 2014
As adult humans, we can distinguish about 10,000 different smells. It’s no wonder, then, that we have so many words and expressions to describe them. This week we’re taking a look at those smell words – words that describe good smells and words that describe bad smells. Most smell words are either

Read More 

high-frequency trading noun

October 27, 2014
a type of stock market trading that uses very complex technology to trade extremely quickly, often making tiny profits which nevertheless add up to substantial sums Lewis’s book, Flash Boys, is driving a huge amount of attention toward the topic of high frequency trading, and it has rekindled some of

Read More