The Manager of wakf property is called a mutawalli. [Mitra’s Legal & Commercial Dictionary]

Under the Mohammadan law, as soon as a wakf is created, all rights of property pass out of the wakf (dedicator) and vest in the Almighty. The mutawalli has no right in the property belonging to the wakf; the property is not vested in him, and he is not a trustee in the technical sense. He is merely a superintendent or manager. [AIR 1922 PC 123]

The warden of a mosque. [P Ramanatha Aiyer’s The Law Lexicon]