1. 屁股：bum 对小孩说的屁股 | hindquarters 屁股 | rectum 直肠

2. 尾部; 两条后腿 (名)：hindquarter 后腿及臀部 (名) | hindquarters 尾部; 两条后腿 (名) | hindrance 妨害, 阻碍物, 障碍 (名)

1. （四足动物的）后腿及后臀
    The hindquarters of a four-legged animal are its back part, including its two back legs.

1. the part of an animal that corresponds to the human buttocks

    Synonym: croupcrouperump

2. the fleshy part of the human body that you sit on

    e.g. he deserves a good kick in the butt
           are you going to sit on your fanny and do nothing?

    Synonym: buttocksnatesarsebuttbacksidebumbunscanfundamenthind endkeisterposteriorpratrearrear endrumpsternseattailtail endtooshietushbottombehindderrierefannyass