phrase often used by nerdy kids to describe bad things

when everything you do seems to suck and/or fail miserably. more over, every attempt you make at everything ends up in horrendous disaster or blowing up in your face.

when victory is close and near at hand, and then complete failure results

terrible failure
failing really bad

a fail so epic it's almost a win.

Josh Evans

To fail at something in such a manner that it is on an epic scale. An epic fail is typically so tragic or humiliating, it may actually be seen as funny to spectators of the event. Typically, the person or persons who took part in or caused the epic fail do not find such hilarity in their failed endeavor so easily. Pwnd is often an accurate word to describe such failure, but is not always a good word for the situation.