I’ll probably be showing my age, but OG is really short for “Original Gangster”. It’s vernacular from the street gang culture and was a term of endearment for the old heads who kept things real. As rap/hip hop became more popular the term became used more and more etc etc. I think the term first got popularized outside of the original culture by Ice T in the early 90s when he released his song aptly named… O.G. Original Gangsta.
Sorry! Carry on…
Sorry! Carry on…