Lang uages, generally, are not created by design; they come about by accident. As such they are messy, inconsistent and constantly evolving. This explains, no doubt, the appeal of made-up languages, which can be fixed and logical in a way that real languages cannot. One of the most famous imaginary languages in literature is that envisaged by Borges in his short story "Tlön, Uqbar, Orbis Tertius." The citizens of Borges's fabulous country, Uqbar, hold to an extreme form of philosophical idealism, conceiving of the world as a "heterogenous series of independent acts." One consequence is that their languages don't contain nouns. Other famous made-up languages include Tolkien's Elvish, and the language of the warlike Klingons in Star Trek, which has become the lingua franca of Trekkies.

But one can have fun with made-up words without going to the bother of inventing a new language. This is something that Douglas Adams and John Lloyd did in their "dictionary of words that haven't yet been invented," The Meaning of Liff, surely the funniest word book ever written. Among the authors' yet-to-be-invented words were shoeburyness ("The vague uncomfortable feeling one gets when sitting on a seat which is still warm from someone else's bottom") and altami ("Practising the art of balancing the hot and cold taps"). The same strain of humour was exploited by Adam Jacot de Boinod in his 2005 bestseller The Meaning of Tingo, a collection of unlikely (though real) words from around the world. The follow-up, Toujours Tingo, is about to be published. Its treasures include okuri-okuri (Japanese for "a man who feigns thoughtfulness by offering to see a girl home and then molests her in the doorway") and the Tsongan rhwe ("to sleep on the floor without a mat and usually drunk and naked").