a person (usually a kid) who downloads their hack programs, and then uses the program to hack others. also, noobs who dont know how to write their own viruses. thus being awarded the insulting name of script kiddy.

Someone on IRC without a clue using destructive and malicous scripts.

See Haxor

In my personal experiences, a script kiddy is one who goes around to various forums, asking how to hack, w/o any previous experience with computers.
See lamer

A person associated in creating scripts, programs, viruses, or trojans aimed at causing harm or grief to their victims. Usually these people are amatures.