A grenade in Call of Duty 4 or Halo 3 that bounces back at the thrower and usually kills him.
"Oh man I just threw a Dave Grenade and it killed me"
A grenade thrown towards an opening to kill the target(s) inside the room, which misses the window and hits the surrounding wall, rebounds and lands next to the thrower.
(Grenade misses opening and bounces off towards player)
Player2:Lol, that noob threw a Dave Grenade!