The Greek word for “Lord” is kyrios, which may mean “master” or “sir.” 

“Lord” should not be confused with “LORD”, the word that is printed in all capital letters (or small-caps) and used to represent God’s special name, “YHWH“ or ”Yahweh.” (See the mini-article called "Lord (YHWH)”) 

In the Roman Empire, “Lord” was used for Caesar and indicated his absolute power as monarch, but did not mean that he was a god. “Lord” appears as a title for Jesus in the New Testament and declares his royal authority as the one who has been raised from the dead to sit at God’s right hand.

Practically speaking, “Lord” functions in the same way as “Christ,” another royal title. When Peter addressed a crowd in Jerusalem, he said, “Everyone in Israel should then know for certain that God has made Jesus both Lord and Christ, even though you put him to death on a cross” (Acts 2.36). Another example of the royal meanings of this title is found in its Aramaic form, maran, which means “Our Lord,” and was used to designate the king in the royal courts. In two places in the New Testament (1 Cor 16.22; Rev 22.20), the Christian community calls upon Jesus to return soon by using the expression maranatha (“Our Lord, come”).

“Jesus is Lord” appears several times in Paul’s letters (Rom 10.9; 1 Cor 8.6; 12.3; 2 Cor 4.5). It is one of the shortest and oldest statements of belief in the New Testament. To affirm Christ as Lord gave great confidence to the early Christians who suffered for their belief that God raised Jesus from death and gave him the highest place and honored his name above all others. As one ancient hymn that Paul quoted said, “So at the name of Jesus everyone will bow down, those in heaven, on earth, and under the earth. And to the glory of God the Father everyone will openly agree, ‘Jesus Christ is Lord!’” (Phil 2.10,11).