The Collaborative International Dictionary of English v.0.48:

Delilah \De*li"lah\, n.
   The mistress of Samson, who betrayed him (--Judges xvi.);
   hence, a harlot; a temptress.
   [1913 Webster]

         Other Delilahs on a smaller scale Burns met with during
         his Dumfries sojourn.                    --J. C.
                                                  Shairp.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Delilah
    n 1: (Old Testament) the Philistine mistress of Samson who
         betrayed him by cutting off his hair and so deprived him of
         his strength
    2: a woman who is considered to be dangerously seductive [syn:
       enchantress, temptress, siren, Delilah, femme
       fatale]