A liturgical exclamation derived through the Greek transcription 'ώσαννά of the Aramaic term hôša’-nā' that represents the Hebrew term hôšî’â-nnâ meaning "Do save (us)!" It occurs in Ps 118.25 as a cry for continued help after victory and a joyous shout of homage to God. This Psalm is one of the Hallel Psalms (Psalms 113–118) that were recited especially at the Jewish feasts of passover, pentecost, booths (tabernacles), and the dedication of the temple. The verse Ps 118.25 was sung during the octave of the feast of Booths once a day and seven times on the seventh day while the priests went in procession around the altar. During the procession on the seventh day, the people waved festive branches (hōšannōt ) and sang hymns of praise with "Hosanna" as their refrain (Josephus, Ant. 3.10.4; 3 Maccabees 10.6–7). This spontaneous acclamation of joy and supplication was sung when Christ entered Jerusalem at His last Passover (Mt 21.9, 15; Mk 11.10; Jn 12.13). In the context here Hosanna expresses the messianic hopes of the people; it is the cry of welcome ("Blessed in the name of the Lord be he who come"—the standard Hebrew formula of welcome) to "the Son of David," i.e., the Messiah. At a very early date (Didache 10.6; Const. Apost. 8.13) the word Hosanna was incorporated in the Christian liturgy at the Sanctus of the Mass; later it was introduced into the Palm Sunday procession.
[m. r. e. masterman/eds.]
ho·san·na / hōˈzanə; -ˈzä-/ (also ho·san·nah) • interj. (esp. in biblical, Judaic, and Christian use) used to express adoration, praise, or joy. • n. an expression of adoration, praise, or joy.