The name Cybil means Soothsayer and is of Greek origin. Cybil is a name that's been used primarily by parents who are considering baby names for girls.
A soothsayer is someone who is able to see the future.
Famous Cybils include: Cybill Shepherd, actress/model. Sybil is a 1973 book by Flora Rheta Schreiber about the treatment of Sybil Dorsett for Dissociative Identity Disorder.