Oxford University Press on Tuesday crowned the word - defined as "a situation that has been comprehensively mismanaged, characterized by a string of blunders and miscalculations" - its top term of 2012.
Each year Oxford University Press tracks how the English language is changing and chooses a word that best reflects the mood of the year. The publisher typically chooses separate British and American winners. This year's American champion is "gif," short for graphics interchange format, a common format for images on the Internet.
The editors said gif was being recognized for making the crucial transition from noun to verb, "to gif": to create a gif file of an image or video sequence, especially relating to an event. And, inevitably, to share it online. Cute kittens, Olympic champions, President Obama - they've all been giffed.
Coined by writers of the satirical television show "The Thick of It," omnishambles has been applied to everything from government PR blunders to the crisis-ridden preparations for the London Olympics.
Oxford University Press lexicographer Susie Dent said the word was chosen for its popularity as well as its "linguistic productivity."
She said "a notable coinage coming from the word is Romneyshambles" - a derisive term used by the British press after U.S. presidential candidate Mitt Romney expressed doubts about London's ability to host a successful Olympics.
Omnishambles was chosen over shortlisted terms including "mummy porn" - the genre exemplified by the best-selling "50 Shades" book series - and "green-on-blue," military attacks by forces regarded as neutral, as when members of the Afghan army or police attack foreign troops. (For American English speakers, it's "mommy porn.")
The Olympics offered up finalists including the verb "to medal," ''Games Maker" - the name given to thousands of Olympic volunteers - and distance runner Mo Farah's victory dance, "the Mobot."
Europe's financial crisis lent the shortlisted word "Eurogeddon," while technology produced "second screening" - watching TV while simultaneously using a computer, phone or tablet - and social media popularized the acronym "YOLO," you only live once.
The final shortlisted term in Britain is an old word given new life. "Pleb," a derogatory epithet for lower-class people, was alleged to have been uttered to a police officer by British Cabinet minister Andrew Mitchell. He denied using the term, but resigned.
Other words on the U.S. shortlist included Higgs boson (as in particle), superstorm (as in Sandy) and "nomophobia," the anxiety caused by being without one's mobile phone.
All the shortlisted words have made a splash in 2012, but editors say there is no guarantee any of them will endure long enough to enter the hallowed pages of the Oxford English Dictionary.