(especially British English, informal) very stupid; not at all sensible. You must be mad to risk it. It was a mad idea. 'I'm going to buy some new clothes.

mad · angry feeling or showing anger:Please don't be angry with me. · mad [not before noun] (informal) very angry:He got mad and walked out. · furious extremely ...

Of a person, action, disposition, etc.: uncontrolled by reason or judgement; foolish, unwise. Subsequently only in stronger use (corresponding to the modern ...

a US humorous magazine, first published in 1952. It uses a cartoon style to make fun of films, advertisements, etc., and to make well-known people look silly.

The earliest known use of the adverb mad is in the Middle English period (1150—1500). OED's earliest evidence for mad is from around 1400, in Pearl.

having strong feelings about something that you dislike very much or about an unfair situation. Her behaviour really made me angry.

a word to describe a person who has a mental illness, which was used by doctors in the past but is now offensive

The expression 'as mad as a hatter', meaning completely crazy, was already common when Carroll wrote the book. Definitions on the go.

​a person who does crazy, stupid or dangerous things. He drove like a madman. Some madman (= stupid person) deleted all the files. · ​(old-fashioned, offensive) ...

having strong feelings about something that you dislike very much or about an unfair situation. Her behavior really made me angry.