Lad

In Britain (there's already loads for definations for the way Australians use this word), this word generally means a young male. However in modern Britain this word has come to mean someone who engages in typical testosterone-driven behaviour such as drinking, sport and having a laugh with mates, sometimes harmless, sometimes obnoxious or even worse antisocial. There was once the phrase "Jack-the-Lad" (a rogue), "laddie" has long been part of the Scottish dialect, and in the 90s something called "Lad-culture" arose, where the aforementioned behaviour was celebrated. Girls who behaved in a similar way were called "Laddettes". There is also the adjective "laddish".