Bargoens
Bargoens is a form of Dutch slang. More specifically, it is a cant language that arose in the 17th century, and was used by criminals, tramps and travelling salesmen as a secret code, like Spain's GermanÃa or French Argot.
However, the word Bargoens usually refers to the thieves' cant spoken in the latter half of the 19th century and the first half of the 20th century. The actual slang varied a lot from place to place; often Bargoens denotes the variety from the Holland region in the Netherlands. While many words from Bargoens have faded into obscurity, others have become part of standard Dutch (but are more often used in the "Hollandic" than in other Dutch dialects). Examples of words now common in Dutch: hufter (bastard), gappen (to steal) and poen (money). As is the case for most thieves' languages, many of the words from Bargoens are either insults or concern money, crime or sex.
Due to the large number of Jews who were travelling salesmen, and because of their position as relative outcasts, Bargoens has many Yiddish loanwords. Examples are sjacheren (to barter), mesjogge (crazy), jatten (hands, to steal), gabber (buddy, friend).
The name of this cant is close to baragouin, which means "jargon" in French. It is supposed to have been derived either from the Breton words bara+gwin (bread+wine) or from Bourgondisch ('Burgundish', i.e. [the language] from Burgundy).