Wanderoo \Wan`der*oo"\, n. [Cingalese wanderu a monkey.] (Zo["o]l.) 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.