It can be used as:
* An adjective: Describing something or someone as peaceful. For example, "la vie paisible" would mean "the peaceful life."
* A noun: Referring to a peaceful person or thing. For example, "la paisible vallée" would mean "the peaceful valley."
It's important to note that "la" is the feminine singular definite article in French, so "la paisible" is specifically referring to something feminine.