A salad is when you stall on the coping on an angle. Kind of like this ---/---
But more closer to your back wheel. I'm not sure if the back wheel has to be touching the qp but as long as its at an angle and your front wheel isn't touching the ground. Think of it like you are low on speed and you pump your way to the top of the qp with just enough speed to stall but not enough speed to get your front wheel down. You kind of hang to jump onto it. It's hard to explain. Hope this helps.
Its basically a disaster, but with your front wheel above the coping instead of the back wheel. And your front doesnt touch. And yeah, its called a salad.