parvenu

French has been generous in providing us with terms for obscure folks who suddenly strike it rich. In addition to parvenu, French has loaned us nouveau riche, arriviste, and roturier, all of which can describe a rich person of plebeian origins, especially one who is a bit snobby. Those colorful and slightly disparaging terms for the newly moneyed clearly show their French heritage, but it may be harder to see the French background of a term Massachusetts locals once used for coastal merchants made rich through the fishing trade: codfish aristocracy. Codfish comes from Middle English (beyond that its origin is a mystery), but aristocracy passed into English via Middle French (it is ultimately from Greek aristos, meaning "best").