lunatic
lunatic Lexical Profile
lunatic Game Scores & Validity
• noun
A person who behaves in an extremely foolish, reckless, or erratic manner.
"The driver swerved across three lanes of traffic like a complete lunatic."
A person who is severely mentally ill or legally declared of unsound mind (now archaic and offensive).
"Under nineteenth-century common law, a certified lunatic could not enter into binding commercial contracts."
• adjective
Wildly foolish, reckless, or absurdly irrational.
"Investing the entire company reserve into an untested venture was dismissed by the board as a lunatic scheme."
Relating to, affected with, or designed for the care of severe mental illness (now chiefly historical).
"Historians of nineteenth-century medicine frequently examine the records of Victorian lunatic asylums."
Word Nuance & Usage
Once a standard medical and legal designation for a person of unsound mind, "lunatic" is now obsolete in clinical and statutory contexts and is regarded as offensive when directed at individuals with mental illness; in modern English, it is used informally for wildly reckless people or ideas.
Word Origin & Etymology
Borrowed in Middle English via Old French lunatique from Late Latin lunaticus ('moonstruck'), derived from Latin luna ('moon'), reflecting the ancient folk belief that intermittent insanity was caused by the changing phases of the moon.