Definition: Generally stands for 'What the duff'. Most people use a question mark afterwards to get the point through. Rather than using the same term for the other 'w's, who, when, where, and why, it makes more sense to actually state the word and follow it with 'tf' Capitalization doesn't really matter. This term can also be likened to 'What the smithwick?' which is more comical and has a tantamount meaning.
Example: Dracula is suddenly woken from his slumber only to find a wooden stake pierced through his heart. Knowing the wooden stake will seal his death for all entirety, he yells out, "What the Duff?!"
