loony

/ˈluni/
adjective
  1. Crazy or silly; not sensible.
    • The movie was so loony that everyone in the theater was laughing.
    • That's a loony idea—we can't build a house out of cardboard.
    • My brother acts totally loony when he stays up too late.
Antonyms
noun
  1. A person who is crazy or acts very strangely.
    • Don't listen to that loony; he thinks aliens live in his basement.
    • The old man on the corner is a harmless loony who talks to pigeons.
    • Some loony tried to pay for groceries with Monopoly money.
Synonyms