A person who is eccentric or unusual in their behavior or beliefs; a peculiar or odd individual.
Of uncertain origin, first recorded in the early 20th century, possibly from a british dialect term meaning "madman" or "simpleton".
- He thought the conspiracy theorist was a kook.
- She was considered a kook by her classmates for her strange fashion choices.
- The new neighbor was a kook and no one wanted to talk to him.
- He was always considered a kook because of his unorthodox ideas.
- The kook was known for his eccentric behavior.