Etymology From Middle English upstarten, upsterten, equivalent to up- + start.
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 mushrooms1627 (indicated as 1626), Francis [Bacon], “VI. Century.”, in Sylua Syluarum: Or A Naturall Historie. In Ten Centuries. […], London: […] William Rawley […]; [p]rinted by J[ohn] H[aviland] for William Lee […], →OCLC:
[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.”1815 December (indicated as 1816), [Jane Austen], chapter XVIII, in Emma: […], volume II, London: […] [Charles Roworth and James Moyes] for John Murray, →OCLC, page 345:
2 more examples
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.2006, Edwin Black, chapter 1, in Internal Combustion:
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.2012 June 29, Kevin Mitchell, “Roger Federer back from Wimbledon 2012 brink to beat Julien Benneteau”, in The Guardian, archived from the original on 15 Nov 2016:
Etymology From Middle English upstarten, upsterten, equivalent to up- + start.
1
Acting like a parvenu.
2
Self-important and presumptuous.
upstart
verb
Etymology From Middle English upstarten, upsterten, equivalent to up- + start.
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.1590, Edmund Spenser, “(please specify the book)”, in The Faerie Queene. […], London: […] [John Wolfe] for William Ponsonbie, →OCLC:
the beauteous beast Scared by the noise upstarted at our feet1859, Alfred Tennyson, “(please specify the page)”, in Idylls of the King, London: Edward Moxon & Co., […], →OCLC:
1 more example
"Be that word our sign of parting, bird or fiend!" I shrieked, upstarting—1845 February, — Quarles [pseudonym; Edgar Allan Poe], “The Raven”, in The American Review, volume I, number II, New York, N.Y.; London: Wiley & Putnam, […], →OCLC: