Sibylline /(?)/

Sib·yl·line

Sibylline

a.
  1. Pertaining to the sibyls; uttered, written, or composed by sibyls; like the productions of sibyls.

Phrases & Compounds
Sibylline books
Books or documents of prophecies in verse concerning the fate of the Roman empire, said to have been purchased by Tarquin the Proud from a sibyl.