"Hoshana" (הושענא) is a Hebrew word meaning please save or save now.  In Jewish liturgy, the word is applied specifically to the Hoshana Service, a cycle of prayers from which a selection is sung each morning during Sukkot, the Feast of Booths or Tabernacles. The complete cycle is sung on the seventh day of the festival, which is called Hoshana Rabbah (הושענא רבא, "Great Hosanna").
"Hosanna" (Greek transcription: ὡσαννά, hōsanna) is the cry of praise or adoration shouted in recognition of the Messiahship of Jesus on his entry into Jerusalem, Hosanna! Blessed is the one who comes in the name of the Lord! It is used in the same way in Christian praise.
Overall, it seems that "Hosanna" is a cry for salvation; while at the same time is a declaration of praise. Therefore, it may be derived that this plea for help is out of an agreeably positive connotation.
The old interpretation "Save, now!" which may be a popular etymology, is based on Psalm 118:25 (Hebrew הוֹשִׁיעָה נָּא hOshEeah-nna) (Possibly "Savior"). This does not fully explain the occurrence of the word in the Gospels, which has given rise to complex discussions.