Source : WordNet®

newbie
     n : any new participant in some activity [syn: {newcomer}, {fledgling},
          {fledgeling}, {starter}, {neophyte}, {freshman}, {entrant}]

Source : Free On-Line Dictionary of Computing

newbie
     
         /n[y]oo'bee/ (Originally from British public-school
        and military slang variant of "new boy") An inexperienced user
        of {Usenet} or other system.
     
        This term surfaced in the {newsgroup} {news:talk.bizarre} but
        is now in wide use.  Criteria for being considered a newbie
        vary wildly; a person can be called a newbie in one newsgroup
        while remaining a respected regular in another.  The label
        "newbie" is sometimes applied as a serious insult to a person
        who has been around {Usenet} for a long time but who carefully
        hides all evidence of having a clue.
     
        See {BIFF}.
     
        [{Jargon File}]
     
        (1998-02-18)