1.Having it all. "I'm in the party ballin' with my posse ah-ha-ha" -- Ying Yang Twins (Dispose of Broadz) 
ballin' not having it all, but showing you have it all..... you can ball without being very rich, as long as you just spend alot.
it comes from basket (or base) ball stars that had big deals, and lots of money to spend
I think it came from drug dealers selling 8-balls who made a lot of money that way.
Larsen from Norway (Giske) is Ballin' with his homies!
Ballin' can also mean crying "But your ballin cuz your beautiful" -Sisqo "Dance 4 Me" No, crying is "bawling".
Ballin' means playing basketball all day long, throwing down "Dunkadelic" facials on all defenders.
being the best n***** on the court
able to throw down fo sho on some nigs