arriviste

noun

1. (derogatory)An upstart or newcomer; nouveau riche; parvenu; an ambitious, brash or arrogant person who has yet to integrate with his or her new social group.

   “The second class in the bureaucracy, among whom are to be found most of the men occupying political posts just below the top, consists of arrivistes, who are enthusiastic Bolsheviks because of the material success of Bolshevism.”