B2 noun /ˈdʒoʊ.kər/
Joker
ジョーカー
Meaning
a playing card with a picture of a jester, used as a wild card; a person who is fond of joking
Example
He used the joker card to complete his winning hand in the poker game.
彼はポーカーの勝ち手を完成させるためにジョーカーを使った。