[rump] n [ME, of Scand origin; akin to Icel rumpr rump; akin to MHG rumph torso] (15c) 1 a: the upper rounded part of the hindquarters of a quadruped mammal b: buttocks c: the sacral or dorsal part of the posterior end of a bird
2: a cut of meat (as beef) between the loin and round--see beef illustration
3: a small or inferior remnant or offshoot; esp: a group (as a parliament) carrying on in the name of the original body after the departure or expulsion of a large number of its members