Derrieres, a French term for buttocks, has numerous synonyms in English, ranging from colloquial to formal. Some of the informal words that could replace derrieres include bum, butt, rear-end, backside, booty, tush, fanny, and keister. These words are commonly used in everyday speech by people of all ages. Whereas, more formal words for derrieres include glutes, posterior, rump, hindquarters, and hind parts. These formal words are more likely to be used in professional or academic settings. Regardless of the synonym used, it is essential to understand the context in which it is appropriate and slang should be used with caution, if at all, in formal settings.