I've always been fascinated by "secret" languages. I grew up with a diverse linguistic background and, as a child, often spoke a polyglot comprised of Finnish, English, Hindi and French. The polyglot would change depending on the group I was with. Living on the west coast of Canada, there're words that are in regular use that derive from the trade language—"skookum" meaning "big" or "strong"; "chuck' meaning "water" i.e. sea. Polari contributed words that we use even here—"popo" for police; "scarper" to take off or run away.