Canticle

A canticle is most basically defined as a non-metrical hymn or song. Its meaning can be expanded to include:

• A song, especially a hymn (as in "Canticle of Canticles", another way to refer to the biblical book Song of Solomon.)
• A canto or division of a poem
• A psalm, hymn, or passage from the Bible, arranged for chanting during a church service (for example the Magnificat.)

From the Latin "canticulum", a diminutive of "canticum", song. From "cantus", singing, "coner", to sing.