Typically used in the custom Warcraft 3 game, dota
. There are a few different types of leavers:
1. Assholes that join a DotA game just so they can leave when the game starts and annoy the piss out of everyone.
2. Assholes that play in DotA games and then leave when they are sucking badly.
3. Complete morons that join in a Dota game and leave the room before the host even starts.