House left is the opposite of stage left. Stage left and right are judged as though you were an actor standing in the center of the stage facing the audience (AKA the house). House left and right are the opposite; left and right from the audience's point of view, facing the stage. These are more likely to be used by the light crew or others working out over the audience than by the stage manager.
AKA Opposite Prompt, OP, and No, your other left!.