n. A new or inexperienced user, especially one who is ignorant of netiquette and other online proprieties.
"There is nothing inherently bad about being an inexperienced user. It's only when the inexperienced ignore those rules that serve to grease the wheels of Net social interaction that they get branded with the 'newbie' label."
This is probably the mildest of hacker insults, and is certainly the most common now that the Internet is flooded with newcomers of all persuasions. Newbie is a variant of 'new boy', which the OED defines as a "schoolboy during his first term at a school, esp. one at a preparatory school or English public school."