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 "Germanía" or French "Argot". It is speculated to originate from Rotwelsch 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 greatly 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). "Hufter" (jerk), "gappen" (to steal) and "poen" (money) are examples of words now common in Dutch. As is the case for most thieves' languages, many of the words from "Bargoens" are either insults or concern money, crime or sex. Bargoens has many Yiddish loanwords. Examples are "sjacheren" (to barter), "mesjogge" (crazy), "jatten" (hands, to steal), "gabber" (buddy, friend), "tof" (great), "hachelen" (to eat). 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). Many Woonwagenbewoners (Dutch Travellers) used to speak this language as well. Examples. Also the nicknames of former Dutch guilders were Bargoens: