Someone who is wise beyond their years. A youngin who already knows what it is....
Chauncey: Damn son, look at that boy...
Sessions: Hoodi Whoooo look at em, over there killen the game.
Chaunce: I guess he already knows what it is bra...
Sessions: Shit, old ass youngin....

Ex. John Wall, Stephen Strasburg, Danny Almante
by softboysoup July 15, 2010
Get the Old Ass Youngin mug.