All I do is ball, nigga, that's my human nature

from Wiz Khalifa (Ft. Amber Rose & Lola Monroe) – Initiation Lyrics on Rap Genius

Meaning

Baller: A ‘thug’ but most commonly a person that has “made it” to the big time. Originally referred to basketball players that made it out of the streets to make millions as a pro ball player, but now is used to describe any thug that is living large and richly. “ball” is a slang term that can also mean work or working hard.
Or since its wiz he could also mean “8 ball” which is smoking crack.
This video describes these lines best:
http://www.youtube.com/watch?v=yJ9ZgsS7sCQ

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