What does "wanderoo" mean?

Wanderoo: A large monkey (Macacus silenus) native of Malabar. It is black, or nearly so, but has a long white or gray beard encircling the face. Called also maha, silenus, neelbhunder, lion-tailed baboon, and great wanderoo. [Written also ouanderoo.] Note: The name is sometimes applied also to other allied species.