Chaos. Anything that is occuring in a haphazardly. The situation is not even thinking about dreaming about having a sense of order. A clustering of items (usually people) in a fucked up way.
When people are trying to get off an airplane and retrieve their baggage from the overhead bins... that is a cluster fuck.
1) An term to describe the use of a large number of people to accomplish a task. The outcome can be negatively affected when too many personnel are applied.
2) A military or online-gaming term for a military screw-up. Usually due to incompetent commanders... often results in friendly fire. Possibly an indication that two many soldiers were needlessly deployed in a small area.
1)
programmer #1: there's like 20 people working on that bug.
programmer #2: uh, I think it'll be a total clusterfuck
2)
soldier #1: awe fuck, I just shot Bobby
soldier #2: we're shooting at our own guys, this is a total clusterfuck!