A fiasco (pl. fiascoes) means a complete or ridiculous failure, especially of a pretentious undertaking.
The word is originally Italian and means a rounded wine bottle, sometimes wrapped by a straw basket, such as used traditionally for the Chianti wine. The metaphorical connection is "they wanted the wine but all they got was an empty bottle."
Fiasco is the English title of a science fiction novel by Stanislaw Lem. It tells about an expedition sent to a distant star in order to make contact with a civilization that had been detected there. The attempt ends, as the title promises, in complete failure.
Fiasco is also a software development project that aims to build a micro-kernel for GNU/Linux.
Some famous fiascoes
The fiasco fiasco
Curiously, in modern American usage, the word fiasco increasingly appears to mean "a mess" more so than "a failure". This misuse is apparent from the context of the many quotes and headlines in today's media and casual conversation. It is further evidenced by the Word of the Day entry on the Random House's website. The author opens by stating that most dictionaries 'give the popular meaning we all know --'a failure, a complete mess'. Contrary to the article, the dictionaries still emphasize 'failure' as part of any acceptble definition, despite the widely acceptable -- and now prevalent -- alternative understanding of the meaning of fiasco by the broad public.