The Greek word for a mediator means one who stands between covenanting parties bringing them into fellowship or forming a channel of communication between them. That is exactly what Jesus (Yeshua‘) did. He came between God and us to reconcile us by His death on the cross. As the perfect man and perfect Son of God, He alone could fulfill the role of mediator.
No name of God like this occurs in the Old Testament, but in Job 9:33 is says: “There is no umpire between us, who may lay his hand upon us both.” The word “umpire” is yakakh. The Greek Old Testament uses mesitēs and translates the verse: “would that our mediator were present, and a reprover, and one who should hear the cause between both.” That describes the role.
Mediator in Greek:
Strong’s Concordance number: 3316
Bible reference: 1 Tim. 2:5
For there is one God, and one mediator between God and men, the man Christ Jesus. (1 Timothy 2:5 KJV)
A similar name of Jesus is Mediator of a new covenant.