Typically, having shat oneself.
Teacher: "No, no, Billy! Clyde had an 'accident'..."
Billy: "Nawp. He shat himself and flew right off that sumbitch!"
(a) Befouling oneself with something vile (see shart for examples).
(b) Getting caught doing something stupid at work that results in a drug screening.
Nurse: Did we have a little accident?
Patient: Accident? *looks down at self with bewilderment*
Nurse: Oh, you must be here for pre-employment screening then.
1. You, the day or night that you were conceived. Usually happens when there's a broken condom involved when your mom and/or dad did not want a child.
2. Your face. In this world you either fall into the beautiful people category, the butterface category, or the fugly category if you're ugly all around. If you have a butterface or if you're fugly, people may say that your face was an accident when God created it.
3. The time when you run your car into someone else's by mistake or intentionally.
Woman: Oh yeah baby!
Man: Aaaarrgghhhh!!! Oh fuck, the condom broke!
Woman: *sweating* We're fucked now.
Man: What can I say...it was an accident.
Guy: What happened to your face? It looks like an accident. Did someone beat you with an ugly stick?
You: *smashes into some brand new expensive car* Oh fuck.
Guy: What the fuck, man?
You: It was an accident!