wild card
noun [ C ] uk/ˈwaɪld ˌkɑːd/ us/ˈwaɪld ˌkɑːrd/
(IN CARD GAME)
百搭牌，变牌
a playing card that does not have any particular value but that can be used to represent any other card
The joker is a wild card that substitutes for any other card to complete a winning hand. 鬼牌可以作为百搭牌替代任何其他一张牌从而帮助赢得一局。
(COMPUTING)
computing specialized（计算机中的）通配符
in computers, a symbol that has no particular meaning of its own so that its space can be filled by any real character that is necessary
The wild cards are represented here by asterisks. 这里通配符用星号来表示。
(COMPETITION)
持外卡的选手
someone who is allowed to take part in a competition, even though they have not achieved this in the usual way, for example by winning games
Phillips is hoping for a wild card entry to the championships. 菲利普斯希望得到外卡参加锦标赛。
(NOT KNOWN)
无法预言的人（或事物）
someone or something whose behaviour is sometimes unexpected
The wild card in this election is the Green Party - no one knows exactly how much support they will get. 本次选举中无法预料的是绿党——没人确切知道他们会获得多少支持。