If we look into the book of Isaiah in the Old Testament we will find the Hebrew word,
moshia'. In the form of a verb the word would be yasha, which is to deliver or save.
So, as I understand it, moshia' is the one who delivers or saves.
(from Hebrew for Christians.com)
Moshia'
Deliverer. One who "makes wide" or "makes sufficient." One who gives freedom from distress and the ability to pursue one's way. Often understood in a "this-worldly" manner or political deliverance, the word is also used to ultimately portray Adonai's deliverance and salvation of he Israel of God. Derived from the Hebrew verb Yasha'. Note that the name for Jesus - Yeshua- is derived from the same root.
Note:
moshia' (Savior) is not etymologically connected with the word mashiach (Messiah), though there is overlap in the concepts between a Savior and the Messiah.
Let me share a brief overview of the book of Isaiah from bible-history.com;
"Isaiah prophesied during one of the worst times in the history of Israel. The Israelites had become so corrupt God was going to remove them out of His sight. He raised up the Assyrian army to be an unmerciful, barbaric, ruthless, an unstoppable war machine. Their military tactics are still applauded today by those who understand the art of war. God called them from their distant land to come and destroy the Jews living in the north, and take them away from their homeland. Isaiah was living in Judah, in the city of Jerusalem during a time when King Uzziah had died. Isaiah prophesied during the reign of King Uzziah, King Jotham, King Ahaz, King Hezekiah, and probably King Manasseh of Judah. His prophetic ministry lasted from about 760 BC until about 720 BC. Isaiah chapter 6 records a powerful vision that Isaiah received of God the King on his throne, and the king called Isaiah to prophesy to His people. This was Isaiah's call to ministry as a prophet of God and it is interesting that it was at a time when king Uzziah had just died. King Uzziah was faithful servant of the Lord and people felt secure under his leadership, but when he died there was almost a panic. This is when the Lord showed Isaiah who was really on the throne. Isaiah was terrified at the sight of God's holiness (Isaiah 6) and when the Lord called him and asked him who will go with this message and Isaiah said "here am I, send me." Isaiah warned Jerusalem about her idolatry, and her foreign alliances, but they scorned him. They did not listen to his warnings and quickly destroy their instruments of idolatry. He prophesied about the Assyrians who would destroy the northern kingdom, they were also good to come to Jerusalem but God would deliver them. But he also told them that eventually the city will be destroyed and captured by the Babylonians, and that a Persian ruler named Cyrus would release the Jews from captivity. Isaiah prophesied more about the Messiah than any other book in the Old Testament. He also described in great detail the blessings of the future kingdom of the Messiah. His coming would be as a lion bringing the day of God's wrath, but he would also first come as a savior who would die for the sins of the people. This was Isaiah's message, the humility and beauty of the Savior."
"Surely He has borne our griefs and carried our sorrows; yet we esteemed Him stricken, smitten by God, and afflicted. But He was wounded for our transgressions, he was bruised for our iniquities; the chastisement for our peace was upon Him, and by His stripes we are healed. All we like sheep have gone astray; we have turned, every one, to his own way; and the LORD has laid on Him the iniquity of us all." Isaiah 53:4-6
We can easily see how the Israelites looked for a savior to free them from their troubles as a nation. I have read that back then, the salvation they sought was more of a corporate salvation for them as a people rather than as individuals. Even when Jesus came and rode into Jerusalem, they looked for a savior that would free them as a people or nation, from Roman rule and restore the kingdom of King David and the Temple his son, Solomon built. Look back to the part above in bold letters. The Israelites looked for the savior who was the first part of the description, the one who would bring the wrath of God.
We as Christians today, see the first part of "The Savior" as in bold above, as what is yet to come. But today we live with the joy of "The Savior" who has come, died on our behalf and brought us salvation, not from an earthly power such as the Egyptians or Romans but from the power of God who clearly tells us the penalty of sin is death. We look to Christ and agree that we need to be saved and acknowledge that Jesus is the One sent by God to deliver us.
As we come close to Christmas, we look to the child sent to us by a loving and merciful Father. With a loving heart, the Father knew because of our sin and wickedness, we had the need to be delivered saved. So God sent Jesus, His Son to bear the punishment and shame on our behalf. Jesus being the only unblemished man in all of creation was the only one who could deliver our salvation. He was the only one worthy enough to pay the penalty for all of mankind's sin and rebellion. Come He did and pay He did, so we as individuals could live with the hope of eternal life.
He delivered us. He saved us. Thus we call Him, Savior, Christ the Lord.
Shout to the Lord, for great is our joy hat our Savior has come and we live each day with the promise of the Good News, that in Him, Jesus Christ we are "saved."