Taken from the movie "I'm Gonna Git You Sucka" - a 1988 film spoof by (and starring) Keenen Ivory Wayans.
Jack Spade (Keenen) returns from the Army to his old neighborhood following the death of his brother, Junebug. The police determine Junebug's death to be the result of an "O.G.", or "Over Gold" — the victim has overdosed on gold chains.
Lieutenant: "So, what do you got for me?"
Officer: "John Doe, between 25 and 30 years of age, cause of death looks like "O.G.""
Lieutenant: "Over Gold!"
Lieutenant: "Any signs of foul play around here?"
Officer: "No sir, looks like a case of just too many gold chains"
NOT GAME, 50 CENT OR G-UNIT.
OG is refering to the pioneers of gangster rap who were in it since the beginning such as Dr Dre, Ice Cube and the late Eazy-E (RIP)
should,I do it the way a down OG nigga would" - Eazy E; "still a nigga"
This stuff is real Orangutan Ganja.