When a friend says they are going to do something, (usually crazy and as a joke) saying bitchcard means they must do that thing in the next 24 hours or they get bitch slapped. Does not work for if statements such as " if that happens, I'll do this"
Person 1: I'm gonna streak around the school!
Person 2: bitchcard
Person 1: shit
The Bitchbonic Plague is as contagious as the Black Death. Side effects may include being a bitch. The only cure is your friends having an intervention with you and them comparing you to the popular kids. If you are one of those popular kids, there is no cure.