It can refer to:
* A person, especially a woman, who is the source of inspiration for a creative artist, writer, or composer. This is the most common usage of the word.
* A particular subject or theme of inspiration. For example, "Nature is his muse."
* In classical mythology, one of the nine daughters of Zeus and Mnemosyne, each representing a different art. These muses were thought to inspire artists and poets.
It's important to note that the word "muse" can also be used as a verb, meaning to inspire someone to create something.