As it's been said multiple times, most people only use it as a way to discredit a player as part of some agenda.
To me it's a guy who's raw stat totals may look good (ppg, rpg, apg etc) but don't provide the expected impact. For example a guy who averages 25 but gets it by breaking out of the offense and it comes at the expense of his teammates. Or a guy like Rondo who we've seen turn down a wide open layup in favor of passing in hopes of getting an assist.
Defensively you can always point to guys who average high steal and block totals, but have to constantly gamble to get those numbers and have no idea about the concept of team defense