[Боевой маг]

всё-таки слэнг..да ещё интернетный!)
а теперь,пожалуйста,ссылочку на статью из этимологического словаря)

Alex, а ты не прочитала полностью.

History

The word newbie is a variant of new boy and comes from British public school and military slang. Newbie has also been considered a variant of new baby. In the 1960s the term "newbie" also had a limited usage among U.S. troops in the Vietnam War as a slang term for a new man in a unit.Its earliest known usage on the Internet may have been on the USENET newsgroup talk.bizarre. The term is believed to have entered online usage by 1981.