lunatic

/ˈluːnətɪk/
adjective
  1. Wildly foolish, crazy, or irrational.
    • She had a lunatic laugh that made everyone in the room uncomfortable.
    • It was a lunatic idea to build a house on the edge of a cliff.
    • The dictator's lunatic policies led the country into ruin.
Synonyms
Antonyms
noun
  1. A person who behaves in a wild, crazy, or very foolish way.
    • My brother is a lunatic when it comes to extreme sports—he'll try anything.
    • The crowd thought the protester was a lunatic, but he was actually making a serious point.
    • Only a lunatic would drive that fast on a rainy night.