What is "rotvaelsk"

Rotvælsk was a secret language (also known as cant or cryptolect) that was spoken in Denmark from early modern times until the turn of the 20th century. It is now extinct. Rotvælsk was used by a social group known as Natmændsfolk who did demeaning and unclean work or panhandled to survive. Both the social group and the language changed through the centuries, but remained associated with crime, loose morals, poverty and low social status.

The language consisted of borrowed and/or distorted words that took the place of Danish words, while keeping the syntax of the speakers' Danish dialect.