derriere (n.)youdaoicibaDictYouDict[derriere 词源字典]
1774, from French derrière "back part, rear," originally an adverb, "behind, behind the back" (12c.), from Late Latin deretro, from Latin de "from" (see de-) + retro "back" (see retro-).[derriere etymology, derriere origin, 英语词源]