Definitions for "Khalifah"
Caliph: Leader of Muslim nation
The word ‘khalifah’ in the Arabic language has two meanings: 1. A person who is someone’s deputy or succeeds someone by assuming his position of power and authority. 2. A person vested with power and authority. The word is usally used in one of two contexts: either as in [2:30] to refer to the position that mankind has been given on earth, or to refer to the leader of the Muslims who acts as a successor in this regard to the Prophet (saws).
successor or vicegerent. Specifically, it refers to the Muslim ruler.