Emily Dickinson Lexicon

ECH'O, n. [L. echo; Gr. ηχω, from ηχος, sound, ηχεω, to sound.]

1. A sound reflected or reverberated from a solid body; sound returned; repercussion of sound; as, an echo from a distant hill. The sound must seem an echo to the sense. Pope.
2. In fabulous history, a nymph, the daughter of the Air and Tellus, who pined into a sound, for love of Narcissus. Lempriere. Johnson.
3. In architecture, a vault or arch for redoubling sounds. Encyc.