Real Dictionary

parvenu
countable noun: If you describe someone as a parvenu, you think that although they have acquired wealth or high status they are not very cultured or well-educated.

parvenu in American English
a person who has suddenly acquired wealth or power, esp. one who is not fully accepted socially by the class associated with the higher position; upstart
being a parvenu
adjective: being or resembling a parvenu
noun: a person who has recently or suddenly acquired wealth, importance, position, or the like, but has not yet developed the conventionally appropriate manners, dress, surroundings, etc

parvenu in British English
adjective: of or characteristic of a parvenu
noun: a person, esp a man, who, having risen socially or economically, is considered to be an upstart or to lack the appropriate refinement for his or her new position