Whip (politics)
A whip is an official in a political party whose primary purpose is to ensure discipline in a legislature. Whips are the party's "enforcers", who typically offer inducements and threaten party members to ensure that they participate according to the official party policy. A whip's role is also to ensure that the elected representatives of their party are in attendance when important votes are taken. The usage comes from the hunting term "whipping in", i.e. preventing hounds from wandering away from the pack.