Secret trade language from Frank/Brian Herbert's "Dune" saga. In the saga, Chakobsa was based partially on languages spoken in India. Centuries ago, there was actually a secret hunters' language called Chakobsa. The name of the language derives from "chak'w" = hunter + "bze" = language in the Adyga (Circassian) languages of the Caucasus Mountains in Russia.
I find the idea of a secret language called "Chakobsa" intriguing.