fool

a person who lacks good judgment

a person who is gullible and easy to take advantage of

a professional clown employed to entertain a king or nobleman in the Middle Ages

make a fool or dupe of

spend frivolously and unwisely; "Fritter away one's inheritance"

fool or hoax; "The immigrant was duped because he trusted everyone"; "You can't fool me!"

indulge in horseplay; "Enough horsing around--let's get back to work!"; "The bored children were fooling about"