The word "rumped" refers to the hindquarters or buttocks of an animal or bird. There are a variety of synonyms for this word, including posterior, rear end, tail end, hind end, and booty. Other words that can be used to describe the same area of the body include behind, backside, buttocks, and derriere. In a more informal or slang context, the word "butt" or "bum" can also be used to refer to this region. While these words may have slightly different connotations or degrees of formality, they all refer to the same general area of the body.