mad hatter disease

noun

erethism (neurological disorder from mercury poisoning)

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Meanings

nounmad hatter disease (uncountable)
  1. uncountableerethism (neurological disorder from mercury poisoning)

Synonyms & antonyms

Also see
erethism

Origin

"During the 18th to 20th centuries, hat makers used mercury to stiffen felt for hats. They used a type of mercury called mercuric nitrate and worked in poorly ventilated rooms. Over time, the hatters inhaled mercury vapors. Many developed symptoms of chronic mercury poisoning, including psychosis, excitability, and tremors. These symptoms became so common in hatters that the phrase “mad as a hatter” was born."

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Cite this entry
APA

mad hatter disease. (n.d.). In WatkinsX Dictionary. Retrieved November 5, 2026, from https://dictionary.watkinsx.com/word/mad%20hatter%20disease

MLA

“mad hatter disease.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/mad%20hatter%20disease. Accessed November 5, 2026.

Chicago

WatkinsX Dictionary, s.v. “mad hatter disease,” accessed November 5, 2026, https://dictionary.watkinsx.com/word/mad%20hatter%20disease.

Source: mad hatter disease on Wiktionary, CC BY-SA 4.0.