The hindquarters are the back part of an animal with four legs: the hips, the bottom, and the back legs as one area. You hear it about horses, dogs, cows, and other animals that walk on four feet. Vets, farmers, and people who ride horses use it a lot; in ordinary chat many people just say the back or the back legs. It is almost always plural — the horse's hindquarters, not one hindquarter — unless a butcher is talking about a cut of meat from that end. Though actually, using it about a person's bottom can sound cold, as if you were talking about an animal, so keep it for animals unless you are in a doctor's notes. It is a calm, slightly technical word: fine in a vet's report, a little stiff in a story about a pet.

後軀（四隻腳動物的後半身、後腿那一帶）