When a jackass does something that causes bodily harm to another a jackass the result is a jackassident, or unplanned jackassery.
When your in you shop sharpening your knife that is assisted opening and some asks, "Have you ever opened this on someone else?", and the other person says, "No", and sticks out his leg. Then the man holding the knife trys it and cuts the persons leg, thus you have a jackassident.
by Jimbob the Bounty Hunter July 01, 2009