Canto \Can"to\, n.; pl. Cantos. [It. canto, fr. L. cantus singing, song. See Chant.]

1. One of the chief divisions of a long poem; a book.

2. (Mus.) The highest vocal part; the air or melody in choral music; anciently the tenor, now the soprano.

Canto fermo[It.]

(Mus.), the plain ecclesiastical chant in cathedral service; the plain song.

Source: Webster's Revised Unabridged Dictionary (1913)