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(as) mad as a hatter
01
used to refer to someone who is in a very chaotic state of mind and is behaving very abnormally
Dialect
American
American
Humorous
Idiom
Informal
What is the origin of the idiom "mad as a hatter" and when to use it?
The idiom "mad as a hatter" dates back to the 19th century and is associated with the hat-making industry. This phrase is used to describe someone who is acting extremely eccentric, irrational, or mentally unstable.
Examples
He was mad as a hatter after three nights without sleep.
