joker
jo-ker
noun
An extra playing card, often depicting a jester, used as a wild card.
"The joker can substitute for any other card."
noun
An incompetent or foolish person, often used dismissively or insultingly.
"Don't be such a joker; get on with your work."
noun
A person who frequently tells jokes or acts in a humorous way.
"He's always the joker of the group."