Strong's #2962: kurios (pronounced koo'-ree-os)
from kuros (supremacy); supreme in authority, i.e. (as noun) controller; by implication, Master (as a respectful title):-- God, Lord, master, Sir.
Thayer's Greek Lexicon:
1) he to whom a person or thing belongs, about which he has power of deciding; master, lord
1a) the possessor and disposer of a thing
1a1) the owner; one who has control of the person, the master
1a2) in the state: the sovereign, prince, chief, the Roman emperor
1b) is a title of honour expressive of respect and reverence, with which servants greet their master
1c) this title is given to: God, the Messiah
Part of Speech: noun masculine
Relation: from kuros (supremacy)
Citing in TDNT: 3:1039, 486
This word is used 751 times:
Revelation 22:21: "The grace of our Lord Jesus Christ be with you"