Just like "my nigga" this term identifies your buddy who is there for you and will help you get in or out of a world of shit if needed.
I just got play off tickets for next weekend! "my negan"
(noun) A term that can be used by Caucasian individuals to address there Africa American peers. Its used in this pronunciation because it's far enough away from saying the word "nigga" that it reduces the chance of getting there ass kicked and can be back peddled as a walking dead reference.
What up my nigga!? What up my negan!?