Refers specifically to the joker card in a deck of playing cards.
The joker in a deck of cards can be used in place of any other card.
Used for a person who jokes around or is the life of the party; can be affectionate or mildly critical depending on context.
He's the class joker and always makes everyone laugh.
I ended up drawing the joker at the end of the Old Maid game.
In our class, he's the joker of the group.