upstart

UK: /ˈʌpstɑː^rt/

US: /ˈʌpˌstɑrt/

US: (n., adj. up′stärt′; v. up stärt′)

WordReference Random House Learner's Dictionary of American English © 2026

up•start /ˈʌpˌstɑrt/   n. [countable]

1. a person who has risen suddenly from a humble position to wealth, power, or importance.

adj. [before a noun]

2. being, resembling, or characteristic of an upstart.

WordReference Random House Unabridged Dictionary of American English © 2026

up•start  (n., adj. up′stärt′;v. up stärt′), n. 

1. a person who has risen suddenly from a humble position to wealth, power, or a position of consequence.
2. a presumptuous and objectionable person who has so risen;
   parvenu.

adj. 

3. being, resembling, or characteristic of an upstart.

v.i. 

4. to spring into existence or into view.
5. to start up;
   spring up, as to one's feet.

v.t. 

6. to cause to start up.

• 1275–1325; Middle English (verb, verbal); see up-, start

up′start′ness, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

upstart noun / ˈʌpˌstɑːt/

1. a person, group, etc, that has risen suddenly to a position of power or wealth
2. (as modifier): an upstart tyrant, an upstart family
3. an arrogant or presumptuous person
4. (as modifier): his upstart ambition