Fuckin' New Guy. Term still used in the western English-speaking armed forces of the west (primarily United States, Australia, United Kingdom and Canada) to denote a new soldier fresh off his basic training. It means they have the basics but no real experience, so they do everything by the book (which is not always best) and they are overly keen and always shut down on long excersices.
Some people stay F.N.G.'s for years, however most switched-on soldiers lose the status within a year.