When there are too many people in a confined space, all of whom have no idea what they are doing. When this happens in a nunnery, it's called a Cloister Fuck.
Any retail establishment on the day after Thanksgiving (Black Friday) is a cluster fuck of the grandest proportions.
by Weehawk30 September 5, 2006
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military use: a situation where nothing will go right, casaulties will occur, evac will not happen, often engineered by the stupid.
"The Bradley got brewed up at the same time inbound arty started dropping, and the whole deal turned into a giant cluster fuck.
by Brian H March 14, 2002
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The planet Earth since the day George W. Bush was first inagurated as President of the United States.
Every country on Earth has been throughly cluster fucked over the past five years.
by jesster79 February 2, 2006
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Military origin, but in general usage.

A total and complete failure due to someone's idiocy.

Also known as "Charlie Foxtrot".
Don't let Jon touch that computer, he's a walking Charlie Foxtrot.
by CF May 1, 2003
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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.
by alllwant April 22, 2005
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To drive on a busy freeway in close proximity to other cars, ignoring the multiple open lanes. Usually entails drivers clustering to the right side of the freeway while two or more left hand lanes are open, causing a dangerous and just stupid scenario at high speeds, greatly increasing the probability of an accident, which is usually caused by one person hitting their brakes, getting rear-ended, losing control of their car. This process repeats for the car that caused the rear-ending, as he/she is then rear-ended, and this goes into a domino effect of destruction, chaos, and sometimes death. Which in some circles, is recognized as Traffic Darwinism, as the less intelligent drivers are sometimes killed by their own stupidity.

Other definitions:

A dense orgy of more than three people where positioning movement is difficult. Often consists of double penetrations and more skin touching than air.
WTF is up with these people! Get out of the way! Look at all that freeway over there! Bunch of cluster fuckers!

I almost got hit by 3 cars on the freeway because all these idiots kept on cluster fucking the road!

Sally really knows how to cluster fuck! I didn't know there were that many places to put a penis!
by notstoppingtohelp February 24, 2010
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When you comment on something on someone's facebook and you get cluster fucked with 100's of notifications
I commented on my friend's photo and now I am cluster fucked
by The Real Marvel Knight November 30, 2011
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