Source : Webster's Revised Unabridged Dictionary (1913)

Eumenides \Eu*men"i*des\, n. pl. [L., from Gr. ? lit., gracious
   goddesses.] (Class. Myth.)
   A euphemistic name for the Furies of Erinyes.

Source : WordNet®

Eumenides
     n : (classical mythology) the hideous snake-haired monsters
         (usually three in number) who pursued unpunished
         criminals [syn: {Fury}, {Erinyes}]