thieves' cant → γλώσσα του ταραφιού, κορακίστικα των ανθρώπων του υποκόσμου, ακαταλαβίστικα των ανθρώπων του υποκόσμου
Thieves' cant or Rogues' cant, also known as peddler's French, was a secret language (a cant or cryptolect) which was formerly used by thieves, beggars and hustlers of various kinds in Great Britain and to a lesser extent in other English-speaking countries.
https://en.wikipedia.org/wiki/Thieves'_cant