A girl who acts like a bro participating in bro-like activities while also keeping up her femininity as a girl hence the "ette". A broette often dresses preppy but will also drink brews and just hang with the guys without losing her sex appeal.
Guy 1- "dude did you see that broette?"
Guy 2- "yeah man she drank brews with us last night and watched the game"
Guy 1- " Wow a hott girl that can chill? She's defintiely a broette"