Answer:
It actually it is from a Hebrew word that literally means, "save now, we pray." It could also mean a cry to the Lord. People sang this before the Crucifixion of Jesus in Calvary. Listen to this song: Hosanna by Hilsong United. It can further explain :).
"Keep the Faith"
In Latin, it would mean 'Hosanna in the Highest'.
In my country in Spanish it would be "Osana en el Cielo", or if you translate this in English it would be "The Holy one is in the Heavens" or "All of God that is in Heaven". There are many different ways to interpret it.