A lunatic is an outdated and often offensive word for someone considered wildly foolish or mentally ill. As an adjective, it describes behavior that seems extremely unreasonable or crazy.
From Latin 'lunaticus,' meaning 'moonstruck' or 'affected by the moon,' based on the belief that the moon’s phases caused mental disturbance. The term was once a medical label but is now mostly avoided in serious contexts.
This word is a fossil of a medical theory: people once truly believed the moon could twist your mind. It’s a reminder that words can carry old science—and old prejudices—long after we’ve stopped believing the original idea.
“Lunatic” comes from historical beliefs linking mental illness to the moon and was used as a legal and medical category to label people with mental health conditions, often justifying confinement and abuse. Women were disproportionately pathologized under such terms, especially when defying gender norms.
Avoid using “lunatic” or “lunacy” to describe people or behavior; it is stigmatizing toward mental health conditions. Use precise, non-pejorative language about behavior or diagnoses when relevant.
["person with a mental health condition","irrational (for behavior, not people)","unsafe","reckless"]
When referencing historical asylums or ‘lunacy’ laws, highlight how women and marginalized people were often institutionalized for nonconformity rather than genuine illness.
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