upstart

noun

1. One who has suddenly gained wealth, power, or other prominence, but either has not received social acceptance or has become arrogant or presumptuous.

   “upstarts […]they call in reproach mushrooms”

   “[S]he has no fair pretence of family or blood. She was nobody when he married her, barely the daughter of a gentleman; but ever since her being turned into a Churchill she has out-Churchill’d them all in high and mighty claims: but in herself, I assure you, she is an upstart.””

   “But electric vehicles and the batteries that made them run became ensnared in corporate scandals, fraud, and monopolistic corruption that shook the confidence of the nation and inspired automotive upstarts.”

   “Where the Czech upstart [Lukáš] Rosol, ranked 100 in the world, all but blew [Rafael] Nadal's head off with his blunderbuss in a fifth set of unrivalled intensity on Thursday night, [Julien] Benneteau, a more artful citizen, used a rapier to hurt his vaunted foe before falling just short of a kill. In the end, it was he who staggered from the scene of the fight.”

2. The meadow saffron.

adj

1. Acting like a parvenu.
2. Self-important and presumptuous.

verb

1. To rise suddenly, to spring

   “Th' Elfe therewith astownd, Upstarted lightly from his looser make, And his unready weapons gan in hand to take.”

   “the beauteous beast Scared by the noise upstarted at our feet”

   “"Be that word our sign of parting, bird or fiend!" I shrieked, upstarting—”