O.G

Original gangster or old guy depends on the context

He's a O.G: noun eg old guy :2) noun; he's a old gangster

O.G.

original glue-sniffer

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

O.G plastics

A group chat where one person always overreacts

OMG GUYS GUESS WHAT
what?
what?????
MY LIPBALM RAN OUT

Therefore the group chat is named O.G plastics