A term used amongst male friends to replace common terms of endearment such as 'pal', 'boss' or 'brethren'.. suggests being linked through blood, only used for close friends.
NK: Na Manz..
JJ: Yo wagwan G..
NK: Just chillin' and ting..
JJ: Ahhh shiii that's my gyal belling me fam, gonna have to bounce..
NK: Yeah no worries bludline, 1.