Player 2: The fuck is Oak?
Player 1: It's 21, bitch.
Player 2: Oh, 21, aiight, my b.
If something is okay, or a girl is okay looking, she would be Oakland A's or in short, Oaks.
You can stress how Oaks a person is by adding Ser (short for serious).
guy two- "that's a fitted."
guy one- "i'm gonna wear it anyway."
guy two- "you're so oaks."