o.g. 

1.Abbreviation for the pseudonym 'Opera Ghost,' as used in the novel "The Phantom of the Opera."

2. Abbreviation for the tag name 'Original Gangster.'

1. 'Your obediant servant, O.G.'

2. Jamal is a true O.G., he fucked up some people in his day.

o.g. by Polythene Pam November 5, 2003

O.G. 

O.G., original gangster (pronounced "oh gee")

An O.G. is a senior gang member who has been in that gang since way back in the day and lived to tell the tale.

These kids act like they're O.G., but they're just punks, kids playing gangster.

O.G. by major_ October 20, 2008

o.g. 

The original or old school version of any animate or inanimate object.

I bought one of them 70's vans with the o.g. designs on the side.

o.g. by King Willy May 13, 2005

o.g. 

short nickname for "orgasm"

boy: Did you really o.g. last night when we had sex?

girl: Yes, it was the best o.g. of my life!

o.g. by chellie December 13, 2003

O.G. 

original glue-sniffer

Lyric in a Beck song, 'In A Cold Ass Fashion'
"O.G.-- original glue-sniffer"

O.G. by Elizabethlol March 10, 2021

O.G. 

O.G. stands for Original Greatest
Someone reincarnated again who is learning how to build up there skills better over and over again.

I am original greatest {O.G.} ask Tupac Shakur

Sorry Kendrick Lamar for killing your vibe

Xoxo
Shorty

O.G. by Shorty is alive and kicking it November 13, 2022

O G 

O G means original gangsta
those tru gangstas from way back in the day that jacked ya and left nothing but you boxers and socks

Biggie and tupac were both OG's

O G by James White July 10, 2004