supreme in authority that is (as noun) controller; by implication Mr . (as a respectful title)

1. he to whom a person or thing belongs, about which he has power of deciding; master, lord

a. the possessor and disposer of a thing

1. the owner; one who has control of the person, the master

2. in the state: the sovereign, prince, chief, the Roman emperor

b. is a title of honour expressive of respect and reverence, with which servants greet their master

c. this title is given to: God, the Messiah