upstart (n.) Look up upstart at
1550s, "one newly risen from a humble position to one of power, importance, or rank, a parvenu," also start-up, from up (adv.) + start (v.) in the sense of "jump, spring, rise." As an adjective from 1560s. Compare the archaic verb upstart "to spring to one's feet," attested from c. 1300.