OG (O.G.) stands for “Original Gangster” in Fortnite. It was originally a rap term, though it's now widely used in a more general sense to indicate that something is “old school” and/or original. ... A player could also be described as an OG if they've been playing Fortnite since around the time it released.

What is OG slang for?

Due to its gang origins, OG is still often used in reference to anything gang or hip-hop related.

What does OG video mean?

OG means "Original Gangster" and "Original" when used in a social-media context.