hindquarter

noun

1. Either rear half of a side of beef, mutton, veal, lamb or by extension from another edible mammal.
2. (in-plural)The hind biped (leg) of a quadruped, or all body parts situated behind the hind legs' trunk-attachment.

   “While Major was speaking four large rats had crept out of their holes and were sitting on their hindquarters, listening to him.”

3. (derogatory, metonymically, plural-normally)Human behind, butt.