The Slang Dictionary

"[...]They also learned the value and application of a secret tongue; indeed, with the Gipsies came in all the accompaniments of maunding and imposture, except thieving and begging, which were well known in this country, and perhaps in every other, long before visitors had an opportunity of teaching them. Harman, in 1566, wrote a singular, not to say droll, book, entitled, A Caveat for commen Cvrsetors, vulgarly called Vagabones, newly augmented and[...]".