Which word refers to a total failure or collapse?

The word "debacle" specifically denotes a sudden and disastrous failure or collapse. It conveys a sense of not just failure, but that such failure has significant and often chaotic consequences. This term is often used to describe situations that result in a complete breakdown—like a failed event or a financial disaster—emphasizing the dramatic nature of the collapse.

In contrast, the other choices relate to various forms of outcomes associated with success or defeat. "Defeat" indicates a loss but does not capture the element of chaos or total collapse implied by "debacle." "Success" and "victory" are even further removed, as they indicate positive outcomes rather than failure. Thus, "debacle" is the most accurate word to reflect a total failure or collapse.