echo
n. countable C1 Advanced Oxford US //ˈɛkoʊ// UK //ˈɛkəʊ// echo
n. a sound that repeats because it bounces off a surface like a wall or a mountain. You hear it a short time after the original sound.
n. a sound or series of sounds caused by the reflection of sound waves from a surface back to the listener.
The children shouted into the cave to hear their echo.
The empty hallway was so quiet that every footstep produced a sharp, hollow echo.
In the vast cathedral, the choir's final note lingered as a fading echo that seemed to hang in the vaulted ceiling for several seconds.
From Ancient Greek Ἠχώ (Ēkhṓ, “sound”).
Usage
The plural is spelled 'echoes'.
Pitfall
I heard an eco in the roomI heard an echo in the roomLearners often confuse the spelling with the prefix 'eco-' (related to the environment).