A date for prom/other social gathering that asks you to go with them and then disappears into obscurity and avoids contact with the person they asked until said event. The end result is a very awkward situation that makes the receiver of the date request wonder why they even said yes in the first place.
Dude 1: "Dude 2, who's Pam going to prom with?"
Dude 2: "Ummm, I have no idea Dude 1, I think its Chad"
Dude 1: "Oh yeahh, Chad asked her like two weeks ago but they haven't seemed to talk since..."
Dude 2: "That's mad awk man, hes such a Deadbeat date to her."