It can be used to describe someone who cannot speak, or something that does not make a sound.
Here are some examples of how "muet" can be used:
* Une personne muette: A mute person.
* Un film muet: A silent film.
* Une lettre muette: A silent letter (in a word).
It's important to note that "muet" can also be used figuratively to describe someone who is quiet or uncommunicative.