Slang for an expensive strap you stole, in other words a pretty gun. Or slang for a girl you got, a bad bitch, pretty girl
"Why you still got that burner for bruh?" "It aint no burner bruh it a Buzi, this shit beautiful l"
"Man this girl my Buzi bruh on God she bad as hell"
Buziness is being busy instead of taking care of business.
Roots is distracted with buziness that he doesn't take time for his business.