"pertaining to or uttered by a sibyl," 1570s, from Latin sibyllinus, from sibylla (see sibyl).
Entries linking to sibylline
sibyl n.
"woman supposed to possess powers of prophecy, female soothsayer," c. 1200, from Old French sibile, sibille, from Latin Sibylla, from Greek Sibylla, a name for any of several prophetesses consulted by ancient Greeks and Romans. The word is of uncertain origin, by Jerome said to be from Doric Siobolla, from Attic Theoboulē "divine wish." Also in Old English as Sibylla.