1. An act of stupidity which costs you $35 million.
2. An accident involving someone shooting his or herself in the leg.
Derived from the name of soon-to-be-former NY Giants wide receiver, Plaxico Burress, and the "accident" of shooting himself in the leg in a night club which simultaneously put him in jail, ended his career, and nullified the rest of his contract.
"Yo, I can't believe that idiot had a Plaxident! Now he has no money left and might go to jail!"