The act of physically diving into your pile of chips when you're winning at poker. Extra points if you break the card table and bring the game to a halt. Based on wealthy avian industrialist Scrooge McDuck's habit of diving into his vault of gold coins.
A: "How did the Texas Hold'em tourney go last night?"
B: "Wesley was getting tired of taking all of our money, so he ended up McDucking. He wouldn't even pay for a new table afterwards."