Junior High age youth use non-sexual meanings of terms they here older (High School/College) young adults use. This is one of a couple meanings the younger crowd has for the term.
After class a couple of classmates refer to a fellow classmate as a "NARB" because of all the talking in class.
Someone who resides in Narbeth, Pennsylvania. Taken from the full word Narbeth. Often viewed as a negative term, or someone who is a nuisance to mankind.
Dude, that kid just ate all my crackers!", "I know, he's such a Narb.