Leeching

Leeching is an MMO term that refers to joining a team, and then not doing anything while everyone else earns xp for you. This may be a form of power-leveling, if it's previously agreed on by the team and you're lower-leveled. If it's not agreed upon, it's just straight-out leeching which is offensive to just about everybody, and will likely result in a kick from the team.