Webster's Revised Unabridged Dictionary · 1913

Ritornelle

Ritornelle , noun

[Italian ritornello, dim. of ritorno return, from ritornare to return: compare French ritournelle.]

(a)
(Music) A short return or repetition; a concluding symphony to an air, often consisting of the burden of the song.
(a)
(Music) A short intermediate symphony, or instrumental passage, in the course of a vocal piece; an interlude.

Also: Ritornello