Furies or Erinyes (ērĭnˈē-ēz) [key], in Greek and Roman religion and mythology, three daughters of Mother Earth, conceived from the blood of Uranus, when Kronos castrated him. They were powerful divinities that personified conscience and punished crimes against kindred blood, especially matricide. They were usually represented as winged women with serpent hair. Their names were Megaera [jealous], Tisiphone [blood avenger], and Alecto [unceasing in pursuit]. When called upon to act, they hounded their victims until they died in a "furor" of madness or torment. In the myth of Orestes they appear as Clytemnestra's agents of revenge. After Athena absolved Orestes of guilt in the murder of his mother, she gave the Furies a grotto at Athens where they received sacrifices and libations, and became euphemistically known as the Eumenides [kindly ones].
See Aeschylus' play, The Eumenides.