a wild card

wild card

1. In a card game, a card that the player can choose to represent any card. He's going to play his wild card as an ace to win.2. Someone or something that is unpredictable. He is too much of a wild card to be a successful candidate. Nobody wants to vote for someone wildly unpredictable. The wild card in this game will be the weather.3. A person or team who is permitted to participate in an event or competition, such as a round of playoffs, without having to adhere to the usual entry protocol. The wild card rarely wins the championship, but anything is possible.4. In computing, a character that is substituted for an unknown character in a search. An asterisk is often used as a wild card in database searches.See also: card, wild

a wild card

You describe someone or something as a wild card when they cause uncertainty because nobody knows how they will behave or what effects they will have. Some Italians think of her as a possible wild card in next year's presidential election. Note: In games such as poker, a wild card is a card that can have any value a player chooses. See also: card, wild