upstart

A person of humble origin who attains sudden wealth, power, or importance, especially one made immodest or presumptuous by the change; a parvenu.

Suddenly raised to a position of consequence.

Self-important; presumptuous.

To spring or start up suddenly.

To start or spring up suddenly.

One who or that which starts or springs up suddenly; specifically, a person who suddenly rises from a humble position to wealth, power, or consequence; a parvenu.

One who assumes a lofty or arrogant tone.

A puddle made by the hoofs of horses in clayey ground. Halliwell. The meadow-saffron, Colchicum autumnale, whose flowers spring up suddenly without leaves.

Starting up suddenly; quickly rising.

Suddenly raised to prominence or consequence; parvenu: as, “a race of upstart creatures,”