Sibylline/ˈsɪbɪlaɪn/adjectiveOf or pertaining to a sibyl or female oracle, especially the Cumaean Sibyl and the Sibylline Books.(by extension) Having oracle-like predicting powers, clairvoyant.Mysterious.Synonyms: enigmatic, sibyllic🔗 Explore synonyms & relationships🌍 See word origin & history