In Greek mythology, Echo (Greek Ηχω) was an Oread who had the job of talking incessantly to Hera, the Queen of the Gods, so that her husband, Zeus, wouldn't get caught in his numerous affairs. According to some sources, Hera caught on to Echo's trick and cursed her to only be able say what others had just said--hence our modern word "echo".
Echo fell in love with a human named Narcissus but he loved only the image of himself, reflected in water. Echo pined away with love for him but Narcissus was unmoved. Gradually, Echo faded until nothing was left but her voice, repeating the last words of others. Narcissus turned into a daffodil.
Alternatively, Echo was a nymph who was a great singer and dancer and scorned the love of any man. This angered Pan, a lecherous god, and he instructed his followers to kill her. Echo was torn to pieces and spread all over earth. The goddess of the earth, Gaia, received the pieces of Echo, whose voice remains repeating the last words of others. In some versions, Echo and Pan first had one child: Iambe.