(in card games纸牌游戏)a card that has no value of its own and takes the value of any card that the player chooses（由持牌人自由决定牌值的）百搭牌，变牌
(sport体育)an opportunity for somebody to play in a competition when they have not qualified in the usual way; a player who enters a competition in this way“外卡” 参赛，“外卡” 选手（指没有正常参赛资格而参赛）
He was given a wild card for the tournament.他获得了参加锦标赛的外卡参赛机会。
She was beaten in the semi-finals by wild card Louise Smith.在半决赛中，她被通配符路易丝·史密斯（Louise Smith）击败。
(computing计算机)a symbol that can represent any letter or number通配符
An asterisk is commonly used as a wild card.星号常常被用作通配符。
a wild-card search通配符搜索
a person or thing whose behaviour or effect is difficult to predict难以预测的人（或事物）；未知因素；未知数
The Nationalist party is the wild card in the election.国民党是此次选举的未知因素。