faux pas
From Longman Dictionary of Contemporary Englishfaux pasfaux pas /ˌfəʊ ˈpɑː, ˈfəʊ pɑː $ ˌfoʊ ˈpɑː/ noun (plural faux pas /-ˈpɑːz/) [countable] MISTAKEan embarrassing mistake in a social situationExamples from the Corpusfaux pas• Mercifully, circumstances now allow me to rectify this faux pas.• Edna was met with a hushed silence fitting for only the most violent faux pas.Origin faux pas (1600-1700) French “false step”