mong

In UK slang, to mong means to vegetate: To be without doing, and the state of mind that comes with this. Tiredness, television, and weed-smoking are all leading causes of monging out, which is to say being subsumed by the mong, and just sort of sitting there.

The origin of the word is unclear; either it is onomatopoeia for the sound sound of an inactive brain, or it derives from mongol, an offensive term for people with Down's syndrome, or possibly mongrel.

Also: I learn from Chambers dictionary that 'mong' (pronounced 'mung') can mean 'a mixture or crowd', hence among. It may also be what a monger does, as in a fishmonger or an ironmonger, but it's hard to be sure.

In UK and Australian slang, the word "mong" is used as a vague insult roughly equating to "idiot", "moron", "prat", etc. For example, "Shane you mong, you burnt the sausages". It is generally used lightheartedly, i.e. you can call your mate a "mong" when they do something dopey without jeopardising the friendship.

The origins of the term are heavily debated. The Australian version is almost certainly a shortening of "mongrel", falling under the category of Insults that Question One's Breeding. The British version is either derived from the Australian insult, or is a shortened form of "mongol" (a derogatory term for a sufferer of Down's Syndrome). Naturally the latter derivation is somewhat more offensive and politically incorrect than the former, so the insulter must be careful that the insultee does not perceive it that way.

Mong can also be used as a verb and adjective, as described by Oolong. Although sharing the same derivation as the noun, in this context the verb or adjective is usually equivalent to "stoned". For example, "Let's get monged" (verb) or "He looks very monged" (adjective).

In modern Norwegian folklore, mong is the term used for 5,400,000,000 Norwegian Kroner. In other words, one mong is 5,4 billion 1987-Kroner, roughly €70 million.

How did it come about?
In the 1980's, state owned oil company Statoil started building a giant refinery at Mongstad outside Bergen. The construction didn't exactly go according to plans, and in 1987 then Statoil CEO Arve Johnsen was forced to announce that the budget had been thoroughly smashed. The project turned out to be one mong over budget, sending Mr. Johnsen headlong into an early retirement after 15 years at the helm.

At the time, about 50,000 houses of reasonable quality could have been built for a mong.

After the infamous announcement by Arve Johnsen, Norwegian media quickly coined the term as an unofficial monetary unit, using it as comparison for budget overruns everywhere.

Even today, the slang still appears from time to time, especially in connection with large government and defense budget overruns.