A nawab or nawaab (Urdu: نوّاب‎) is an honorific title ratified and bestowed by the reigning Mughal emperor to semi-autonomous Muslim rulers of princely states in South Asia. "Nawab" usually refers to males; the female equivalent is "begum" or "nawab begum". The primary duty of a nawab was to uphold the sovereignty of the Mughal emperor along with the administration of a certain province. The term "nawab" was originally used for the subahdar (provincial governor) or viceroy of a subah (province) or region of the Mughal empire.