1: To dominate so thoroughly, and spectacularly in any competitive event (i.e. sports, video games, etc.) that it seems like the shit you are doing is impossible.
Person A (reffering to GH3): "I just 100% Through the Fire and Flames on Expert!"
Person B: "You just nastified that shit!"
Person A: (reffering to Super Smash Bros. 64): "Yo who's tryin to get nastified by Falcon?"
Person B: "Whatever son, I guarantee you won't nastify like last game with all 15 kills."
After dropping 25 in the fourth to win the game. "Damn nigga, I nastified last night in the fourth!"