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1.
An individual who invests in a company during its start-up phase; a financial supporter in the early stages of a corporation's existence.

An 'angel' is a winged creature from heaven who is supposed to help you when you are in danger. An 'angel investor' is someone who provides money for young businesses that really need it. The phrase was first used to describe wealthy patrons who kept Broadway plays on stage despite a lack of profits.
The company never would have survived without the backing of its angel investors.
by VAKI5 May 10, 2005