lunatic
UK: ˈluːnətɪk | US: ˈluːnətɪk
n. a person who is mentally ill (archaic or offensive)
adj. wildly foolish or irrational
The word "lunatic" originates from the Latin luna (moon), reflecting the ancient belief that insanity was influenced by the phases of the moon. The suffix -tic (from Greek -tikos) denotes a condition or characteristic. Historically, "lunacy" was linked to the idea that erratic behavior coincided with lunar cycles, a notion perpetuated in medieval medicine and folklore. Over time, the term evolved to describe irrationality or madness, though its clinical usage is now considered archaic and offensive.
In the past, people accused of being lunatics were often mistreated.
His lunatic idea to sail alone across the ocean shocked everyone.
The old asylum was built to house so-called lunatics.
She laughed at his lunatic scheme to build a flying car.
The full moon was once thought to trigger lunatic behavior.