Character in Greek mythology who, with Megaera and Tisiphone, comprised the three Erinyes (6)
I believe the answer is:
alecto
(Other definitions for alecto that I've seen before include "Fury (Greek myth)" , "One of the Furies; locate (anag.)" , "Fury exhibited" , "One of classical Furies" , "A fury; locate (anag.)" .)