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"
Combination of the term bitch, which means someone who complains, yells, and is always in a bad mood, and retard, which means someone who consistently does incredibly stupid things.
Definition: A whiny and bitchy person who is constantly acting like a retard.