femme fatale
n.
"attractive and dangerous woman," 1895, from French femme fatale, attested by 1844, from French femme "woman," from Latin femina (see feminine) + fatale (see fatal).
Une femme fatale est une femme qui porte malheur. [Jules Claretie, "La Vie a Paris," 1896]
Earlier, such a woman might be called a Circe.