arriviste 
November 7, 2004 | 21:22

Dictionary.com/arriviste:

arriviste (a-ree-VEEST) noun

  1. A person who has recently attained high position or great power but not general acceptance or respect; an upstart.
  2. A social climber; a bounder.

[French, from arriver, to arrive, from Old French ariver. See arrive.]