Parvenu (7)
I believe the answer is:
upstart
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">parvenu</span>' is the definition.<br/ ><span class="explanation-format__explanation">(synonyms)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for upstart that I've seen before include "Person who has suddenly risen in wealth or importance" , "Arrogant newcomer" , "One who suddenly rises from nowhere to importance" , "Person who behaves arrogantly in the new position" , "Person suddenly risen in world, and arrogant" .)