Echo comes from Greek ekhe meaning “sound”. This was the name of a nymph in Greek mythology who loved talking and often used her loquaciousness to distract Hera when Zeus was off on one of his affairs. When Hera found out, she cursed Echo so that she could only repeat the last thing someone else said. Echo also fell in love with the youth Narcissus but because she couldn’t speak to him, he spurned her advances and she wasted away to nothing because of her unrequited love.
Echo is also a word in English derived from the same source above, used to refer to a sound made by an echo, which is why I decided to list it as a unisex name.