It comes from the Greek word "ηχή" (ēchē), meaning "sound".
Here's how it's used:
* Echoes in sound: A sound that is reflected back, like a shout in a cave.
* Echoes in meaning: Repeating or mirroring something, like an echo of an earlier event or a thought.
The word "echo" is used in many different contexts, including:
* Echolocation: Animals using sound to locate objects.
* Echo chamber: A group of people who only hear opinions that reinforce their own, creating an echo of their beliefs.
* Echo effect: The tendency for people to repeat the behavior of others.
So, the core meaning of "echo" is all about repetition and reflection.