Echo is a word with multiple meanings:
1. In physics, echo refers to the reflection of sound waves that can be heard again.
2. In computing, echo is a command that displays messages or enables/disables command echoing.
3. In Greek mythology, Echo was a nymph cursed to only repeat the words of others.
4. In everyday language, echo can mean a close imitation or repetition.
5. Echo is also the name of Amazon's smart speaker product line.