Definition of 'Archangel'
An angel investor who has invested in a number of ventures that have achieved fame and fortune as commercial successes. An angel investor with this degree of success may also be referred to as a "super angel."
The term may also refer to an external advisor hired by a group of angel investors to perform due diligence and provide advice on business opportunities that are being considered by the group.
Investopedia explains 'Archangel'
Angel investors are high net worth individuals who deploy their own funds to provide startup capital to promising early stage ventures. Silicon Valley, where many of the world's biggest technology companies got their start, is home to numerous archangels. While most angels are active and hands-on investors, they may sometimes need the services of an archangel (external advisor) in areas such as legal and business development.