Word.ws English Dictionary

mad as a hatter

UK/ˌmæd æz ə ˈhætə//ˌmæd æz ə ˈhætɚ/

mad as a hatter adjective: crazy or demented.

Adjective

mad as a hatter (not comparable)

  1. Crazy or demented.
    • He's a very good fellow, but as mad as a hatter. He's called Madman, you know. And never was such a fellow for getting all sorts of rum things about him. He tamed two snakes last half, and used to carry them about in his pocket; and I'll be bound he's got some hedgehogs and rats in his cupboard...1857, [Thomas Hughes], chapter III, in Tom Brown’s School Days. […], Cambridge, Cambridgeshire: Macmillan & Co., →OCLC
    • "I think he’d be as mad as a hatter at your insinuation that he would invite any of his wives, if all I hear of him is true; and what I’ve heard, Wolsey has told me."1895, John Kendrick Bangs, chapter 7, in A House-Boat on the Styx

Examples of mad as a hatter in a sentence

  • He's a very good fellow, but as mad as a hatter.1857, [Thomas Hughes], chapter III, in Tom Brown’s School Days. […], Cambridge, Cambridgeshire: Macmillan & Co., →OCLC:
  • I think Adam Wayne, who is as mad as a hatter, worth more than a million of you.1904, Gilbert K[eith] Chesterton, “The Experiment of Mr. Buck”, in The Napoleon of Notting Hill, London; New York, N.Y.: John Lane, The...
  • Mad as a hatter." No doubt it was very eccentric, and yet the performance struck me as extraordinarily clever and amusing.1913, Arthur Conan Doyle, “The Blurring of the Lines”, in The Poison Belt […], London; New York, N.Y.: Hodder and Stoughton, →OCLC, page 31:
  • Sometimes, I feel sure he is as mad as a hatter; and then, just as he is at his maddest, I find there is method in his madness.1920 October, Agatha Christie, “The Arrest”, in The Mysterious Affair at Styles […], New York, N.Y.; London: Grosset & Dunlap, published...

Synonyms of mad as a hatter

All synonyms of mad as a hatter

Origin of mad as a hatter

First recorded 1829. Of uncertain origin, though usually explained as referring to hat-makers suffering from Erethism due to handling mercury-contaminated felt. Derivation from Old English ātor (“poison”) or its descendant English atter lacks evidence.

Questions about mad as a hatter

What does mad as a hatter mean?
Mad as a hatter means crazy or demented.
How do you use mad as a hatter in a sentence?
He's a very good fellow, but as mad as a hatter.
What part of speech is mad as a hatter?
Mad as a hatter is an adjective.
How do you pronounce mad as a hatter?
Mad as a hatter is pronounced /ˌmæd æz ə ˈhætə/ (UK).

Words near mad as a hatter in the dictionary

  1. mad as a bear with a sore head
  2. mad as a box of frogs
  3. mad as a brush
  4. mad as a cut snake
  5. mad as a fish
  6. mad as a hatter
  7. mad as a hornet
  8. mad as a March hare
  9. mad as a meat axe
  10. mad as a mongoose
  11. mad as a wet hen

Source and license

Adapted from Wiktionary: mad as a hatter (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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Pronunciation audio from Wikimedia Commons, each file under its own free license: en-us-mad as a hatter.ogg, en-au-mad as a hatter.ogg.

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