Definitions

1. adjective

being the most mischievous or naughty

“My little brother is considered the naughtiest in our family during the holidays.”

2. noun

the most naughty person or thing

“The naughtiest kid in the class was always getting into trouble.”

3. adverb

in the most naughty or mischievous way

“The kids played naughtiest at the amusement park last night.”