lunacy
/ˈluːnəsi/
noun
- Extremely foolish or unreasonable behavior; madness.
- It would be sheer lunacy to drive through the floodwaters.
- The plan to build a roller coaster on the roof was pure lunacy.
- Some people called his decision lunacy, but he believed it was brave.
- A historical term for mental illness or insanity.
- The old law used the word lunacy to describe severe mental disorders.
- In the 1800s, people with lunacy were often sent to asylums.
- Doctors once believed lunacy was caused by the phases of the moon.