ECHO, in Poetry, a kind of composition wherein the last words or syllables of each verse contain some meaning, which, being repeated apart, answers to some question or other matter contained in the verse; as in this beautiful one from Virgil:
Crudelis mater magis, an puer improbus ille?
Improbus ille puer, crudelis tu quoque mater.
The elegance of an echo consists in giving a new sense to the last words; which reverberate, as it were, the motions of the mind, and by that means affect it with surprise and admiration.