Definition of "vates"

[Percy Bysshe] Shelley, a true vates, was called upon by their divine influence to render some choice passages from this very Faust, which, from confessed inability, [Francis Leveson-]Gower had left unattempted in his precious version, and some which from other motives he had purposely reticensed.

1833 May, “Hayward’s Translation of Goethe’s “Faust””, in Fraser’s Magazine for Town and Country, volume VII, number XLI, London: James Fraser […], page 532, column 1

The volume is haunted by the death of the vates (poet-prophet) Orpheus, who failed to revive Eurydice from death and was then torn apart by maenads.

1999, Dennis Richard Danielson, The Cambridge Companion to Milton, Cambridge University Press, page 57