Dictionary:

Benedictus

  (bĕn'ĭ-dĭk'təs)

1. 1. A canticle that begins Benedictus Dominus Deus Israel (“Blessed be the Lord God of Israel”).
   2. A canticle that begins Benedictus qui venit in nomine Domini (“Blessed is he that cometh in the name of the Lord”) that forms the end of the Sanctus in the Roman Catholic Mass.
2. A musical setting for either of these canticles.

[Latin, past participle of benedīcere, to bless. See benediction.]

(Lat. : ‘blessed’)

In the Roman rite, part of the Sanctus after the first Hosanna, consisting of the sentence ‘Benedictus qui venit in nomine Domini’ and followed by the second Hosanna. An adaptation from Matthew xxi.9, it is found in the Roman liturgy from the 7th century; it is also sung in various oriental rites. In Renaissance and later masses it is usually a separate section, often for fewer voices.

‘Benedictus’ is also the first word of four canticles (those of David, Azariah, the Three Young Men and Zachary), outside the psalter, which are used in various rites.