New Word: "Slumper"

I learned a new word last week: a "slumper." From what I can tell, this word is familiar to police officers and first responders and is used as a noun. It refers to a vehicle that is otherwise functioning but is stopped at an intersection with a green light and not moving because the driver has passed out. It can be used in a sentence like this: "I was called to a report of a slumper at the intersection of Main and First," or "I came upon a slumper blocking traffic at a green light."

When I read that, I laughed out loud. And in that particular case, you could say it was a "double slumper," because the passenger was also taking a nap when the officer peered into the window.