What is "achalananda"

Achalananda (born Kedarnath Moulik in 1876, died 1947), popularly known as Kedar Baba, was a direct monastic disciple of Vivekananda and the founder of Ramakrishna Mission Home of Service, in Varanasi. He initially worked as a policeman, but was then influenced by the ideology of Vivekananda.