Derivative from the term “Fuk up” / A term used when something / someone behaves less than satisfactory / a plan goes wrong etc.
To “Fuk Up “ - is to admit failure / unsatisfactory result of task / Kiss your friends Girl , forget to book a Taxi home etc.
When two or three “Fuk up's” manifest in succession or to “Fuk Up” which may result in previously uncharted levels of a displeasure – you will know when a “Clusterfuk” has occurred.
Example of a Modern time “Culsterfuk” - When President G.W Bush invaded Iraq – it was widely considered at the time to have been a “Fuk up” - as time passed by, the general consensus Worldwide is that it was indeed a “Clusterfuk”
Other such examples of a “Clusterfuk” - Hitler's invasion of Russia in winter. Napoleons invasion of Russia in winter. Shagging your best friends wife , thus ending a life long relationship with him and indeed your close family circle. Getting caught doing something that may result in 3- 5 years prison time. Getting drunk and joining the Army. Being unfortunate enough to have been born in Ireland.