Source : Webster's Revised Unabridged Dictionary (1913)

Vestal \Ves"tal\, a. [L. Vestalis belonging to Vesta, vestal.
   See {Vesta}.]
   Of or pertaining to Vesta, the virgin goddess of the hearth;
   hence, pure; chaste.

Vestal \Ves"tal\, n. [L. Vestalis (sc. virgo): cf. F. vestale.
   See {Vestal}, a.]
   1. (Rom. Antiq.) A virgin consecrated to Vesta, and to the
      service of watching the sacred fire, which was to be
      perpetually kept burning upon her altar.

   Note: The Vestals were originally four, but afterward six, in
         number. Their term of service lasted thirty years, the
         period of admission being from the sixth to the tenth
         year of the candidate's age.

   2. A virgin; a woman pure and chaste; also, a nun.

            How happy is the blameless vestal's lot! --Pope.

Source : WordNet®

vestal
     adj 1: of or relating to Vesta; "vestal virgin"
     2: in a state of sexual virginity; "pure and vestal modesty";
        "a spinster or virgin lady"; "men have decreed that their
        women must be pure and virginal" [syn: {pure}, {virgin}, {virginal},
         {virtuous}]
     n : a chaste woman