The gap-year video spoof that went viral

He came, he saw, he chundered. A three-minute comedy sketch called Gap Yah has turned globetrotting posh boy, Orlando, into a YouTube sensation. In the last two weeks nearly half a million people have watched the video, with tens of thousands more viewing it every day. It has spawned its own T-shirts, several fan pages and even a dance music remix.

The sketch's creator, actor Matt Lacey, says, "It's a satire on the great number of people who seem to be leaving these shores to vomit all over the developing world."

The private-school equivalent of Little Britain's Vicky Pollard, Orlando is a parody of the pashmina-wearing, point-missing upper-middle-class idiot known as the Rah. Indigenous residents of older universities and public schools, Rahs are known for their ostentatiously unkempt hair, expensive clothes and tediously drawn-out vowels.

If you have not been to Durham, Bristol or St Andrews, however, you may never have encountered the gap-year Rah and his inventive use of the English language. Here then, for your "spiritual – cultural – political" enlightenment, is our beginner's guide to Rahspeak.

Gap Yah – A year's holiday spent in various developing countries getting very drunk on cheap local alcohol, reaching profound moral epiphanies and then vomiting "everywah".

Burmah, Tanzanah and Perah – Burma, Tanzania and Peru. Suitable gap-year destinations. Subsections of Africah, South Americah and Asiah. See also: Darfah.

On the lash – The act of getting very drunk.

Chunder – To vomit. A triumphant act, to be celebrated and, whenever possible, shared. Usually in graphic detail.

Chunklets - The aforementioned graphic detail.

Vomcano – The effect of chundering on the snow on a mountain in Peru after "getting a sense of the awesome power of nature and the insignificance of man".

Oh My God – Expression used to signify that something, even something of no significance whatsoever, has happened. An acceptable way of interrupting someone mid-sentence. Often abbreviated to "Oh Em Gee", or even "Oh My Gee."

Tom Meltzer