noob: newbie; an annoying person (slang)
From Dictionary.com a noob is someone who is new to anything. The term noob itself is widely used in Internet including in gaming and forums hierachy. Anybody new will be labelled a noob as his skills are limited and still has much to learn from the oldies. Though it may sound derogatory, even the oldies themselves were once noobs. So to those noobs out there, be cool and try to learn as much as possible.