Source : Webster's Revised Unabridged Dictionary (1913)

Sibyl \Sib"yl\, n. [L. sibylla, Gr. ????.]
   1. (Class. Antiq.) A woman supposed to be endowed with a
      spirit of prophecy.

   Note: The number of the sibyls is variously stated by
         different authors; but the opinion of Varro, that there
         were ten, is generally adopted. They dwelt in various
         parts of Persia, Greece, and Italy.

   2. A female fortune teller; a pythoness; a prophetess. ``An
      old highland sibyl.'' --Sir W. Scott.

Source : WordNet®

sibyl
     n 1: a woman who tells fortunes
     2: (ancient Rome) a woman who was regarded as an oracle or
        prophet