Webster’s Revised Unabridged Dictionary · 1913
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.