Vanglemesht

Vanglemesht is a language spoken by an unknown group of people on the Disc.

It, although not the people who speak it, has been mentioned twice thus far in the Discworld series. First, in The Colour of Magic, it is mentioned as one of many languages that Rincewind can speak. In fact, he attempts to speak in Vanglemesht to Twoflower, but does not succeed. (The only common language between Twoflower and Rincewind turns out to be the language of Trob).

The second mention occurs in Pyramids as one of the seven languages that Teppic learned at the Assassins' Guild school. It, along with Morporkian, Ephebian, and Laotation (possibly meant to be Latatian?) and several others (which he received poor marks in) are spoken by Teppic, as well as Vanglemesht. However, to the dismay of Dios, Teppic cannot speak or read ancient Djelibeybian...