The Collaborative International Dictionary of English v.0.48:

Seductress \Se*duc"tress\, n.
   A woman who seduces; a female seducer.
   [1913 Webster]

WordNet (r) 3.0 (2006):

seductress
    n 1: a woman who seduces

Moby Thesaurus II by Grady Ward, 1.0:

35 Moby Thesaurus words for "seductress":
   Aspasia, Circe, Delilah, Don Juan, Jezebel, Lorelei, Messalina,
   Parthenope, Phryne, Siren, Thais, adventuress, charmer, coquette,
   courtesan, demimondaine, demimonde, demirep, enchanter,
   enchantress, enticer, femme fatale, flirt, harem girl, hetaera,
   houri, inveigler, odalisque, seducer, siren, teaser, tempter,
   temptress, vamp, vampire