Here are some examples:
* "The naughty dog chewed on the furniture." (Describing the dog)
* "She gave him a naughty wink." (Describing the wink)
However, it can also be used as a noun in certain contexts, usually referring to something considered mischievous or improper:
* "He's always up to some kind of naughty."
* "Don't get into too much naughty."
The context will determine the part of speech.