My Strong*s Greek dictionary says that the word Hosanna means Oh Save and that it is an exclamation of adoration. I once heard a similar definition that Hosanna means Save now! I have not been able to find the source of that definition but I do not doubt it. When we pray we often want the answer to our prayers NOW and not later.
Matthew 21:9: And the multitudes that went before, and that followed, cried, saying, Hosanna to the Son of David: Blessed is he that cometh in the name of the Lord; Hosanna in the highest. 15 And when the chief priests and scribes saw the wonderful things that he did, and the children crying in the temple, and saying, Hosanna to the Son of David; they were sore displeased,
Mark 11:9: And they that went before, and they that followed, cried, saying, Hosanna; Blessed is he that cometh in the name of the Lord: 10 Blessed be the kingdom of our father David, that cometh in the name of the Lord: Hosanna in the highest.
John 12:13: Took branches of palm trees, and went forth to meet him, and cried, Hosanna: Blessed is the King of Israel that cometh in the name of the Lord.
It should be noted that their cry of Hosanna, was a cry for the Messiah, who would fulfill the messianic prophecy from Psalm 118. They wanted Jesus to establish the messianic Kingdom, NOW. They were crying for political deliverance, and yes, they thought He was the long-awaited Messiah but they totally misunderstood the multifold ROLE of the Messiah. Their cry was not a cry for personal salvation at all, it was for political deliverance. This event took place on the Sunday before our Lord*s crucifixion the following Friday. The day after His triumphal entry Jesus cursed the fig tree, a sign of Israel*s rejection because Israel had rejected JESUS. The crowd was very fickle in that they did not understand WHO HE REALLY was. While they cried FOR HIM on that Sunday, a few days later these same people cried CRUCIFY HIM because he did not establish the KINGDOM according to their wishes.
Note too that the chief priests and scribes were sore displeased to see Jesus* power and hear the Hosannas because they did not want to lose the positions and authority they had under the Romans. I hope that some of those Israelites later came to an understanding of who Jesus is and did ask Him to save them. Before I heard the definition Oh save I only understood Hosanna as an exclamation of adoration. I think of it very differently now. It can be a much more meaningful prayer for us than it was to the Israelites. Note that they didn*t just say Hosanna. They CRIED Hosanna. Would that we would cry as earnestly for salvation and deliverance from the influence of Satan as they did for deliverance from the Romans.