Definition of "loony" in English

adjective

1. (informal, offensive, derogatory, of a person) Insane.

   • loony scheme
   • completely loony
   • They dismissed his loony ideas.
   • The movie is full of loony characters.

2. (informal, offensive, derogatory, of a thing) Very silly, absurd.

noun

1. (informal, offensive, derogatory) An insane or very foolish person.