1. something unpredictable and outside the normal rules
2. someone or something that is pretty much picked at random ( both senses from poker)
It looks like the wild card won't help you here.
1) A card that can used as any card in a game of poker.
2) A person who is surprisingly good at everything.
3) A person who doesn't have a defined set of characteristics and has a random set of talents/skills. This person is often very unpredictable.
1) If dealer calls aces as the wild card, 1,2,Ace,4,5 would be a straight.
2) Brian: hey Daniel how did your game go?
Daniel: Good I threw 40 yard pass with 10 seconds on the clock to win the game.
Brian: what you doing now?
Daniel: studying for my calculus test I don't want to loose my 4.0 gpa.
3) John: I can fix the car.
Joe: Really? I always thought you were just a smelly hippie burnout.
John: No, I don't even smoke weed and I hate hippies.
Joe: But.. your wearing a tie dye shirt and you have dreadlocks ....
when your chillin with your boys and very unexpected, yet suprisingly welcome events/phrases are presented to you; shouting out "wild card", is a way of "calling out" such events
sickfootballplayer1: u chillin?
sicksoccerplayer1: im chillin
sicksoccerplayer2: nice nice
slutsophmorewiththepornostarvoice: i like to rub my clit when i think about other girls!
sickathletes in unison: damn, wild card!