Wiktionary
alt. An organisation that coordinates the activities of a number of member organisations and hence promotes a common purpose. n. An organisation that coordinates the activities of a number of member organisations and hence promotes a common purpose.
Usage examples of "umbrella organisation".
They were Feurish, some sort of political scholar who spoke for the great red-brown equatorial band they could see beneath them, Chintsion, who was the current chief-of-chiefs of an umbrella organisation representing all their clubs and other voluntary organisations (sounded insulting, but allegedly their 'clubs' included their supposedly highly effective military) and Peripule, who was the City Administrator of their largest city, though this was not a capital city in the accepted sense, and apparently being voted to be City Administrator was regarded as an imposition, not an honour or a chance to enjoy power.