Corpse camping refers to the process of a player camping specifically next to the enemy's corpse (or, less often, by the closest graveyard) with the purpose of continuously killing that enemy as soon as their resurrection takes place. The term is most commonly used in reference to PvP server practices of one player stalking another (either by using stealth or other means) and killing them upon resurrecting, for no honor. Although this is frustrating to the camped player, this is considered griefing by Blizzard and is subject to punishment by Game Masters.
Waiting for players to resurrect at a graveyard while flagged as PvP is also considered corpse camping, even thought there technically may be no corpse.
And what better way to spend your time than waste it. Instead of resorting to basically doing nothing but making another player miserable, why not use your time better and go outside? It's probably been a while since you've let the sun kids your skin, this will help you actually get a girlfriend. Girls don't like corpse campers, they like real men with honor.
When you do this, it just means that you not only ware their time, you also waste yours. What's your time worth to you? Apparently not much and that says a lot about your life.