Possible Definitions:
1. Echo (n.) A sound reflected from an opposing surface and repeated to the ear of a listener; repercussion of sound; repetition of a sound.
2. Echo (n.) Fig.: Sympathetic recognition; response; answer.
3. Echo (n.) A wood or mountain nymph, regarded as repeating, and causing the reverberation of them.
4. Echo (n.) A nymph, the daughter of Air and Earth, who, for love of Narcissus, pined away until nothing was left of her but her voice.
5. Echo (v. t.) To send back (a sound); to repeat in sound; to reverberate.
6. Echo (v. t.) To repeat with assent; to respond; to adopt.
7. Echo (v. i.) To give an echo; to resound; to be sounded back; as, the hall echoed with acclamations.
8. Echo (n.) A signal, played in the same manner as a trump signal, made by a player who holds four or more trumps (or as played by some exactly three trumps) and whose partner has led trumps or signaled for trumps.
9. Echo (n.) A signal showing the number held of a plain suit when a high card in that suit is led by one's partner.