nouveau riche
wealthy person whose fortunes are newly acquired, and who is therefore perceived to lack the refinement of those who were raised wealthy
en-US/ˌnuˈvoʊ ˈɹɪt͡ʃ/
en-GB/nuːvəʊ ɹiːʃ/
wealthy person whose fortunes are newly acquired, and who is therefore perceived to lack the refinement of those who were raised wealthy