The Meaning of "G"

motorheadFat, drunk and stupid is no way to go through life
Why does LeBron James sign his Twitter comments "G"?
I looked it up on urban dictionary and it could mean "gangsta" (or apparently now gansta). But LeBron doesn't seem like a gangsta.
Does it mean he found the G-spot?
Comments
last commentI really need a catch phrase!
Catch phrases are just brilliant!
Is Gatorade one if his sponsors? You know what corporate whores all those athletes are these days.
No, Gatorade is not a sponsor of Lebron's. You're right about the athletes being corporate whores nowadays though.
G is for gangsta. He's always talking about someone else when he says G.
LeBron shoots.......and scores!.....He hits another G