Around the beginning of the eighteenth century, English thieves' cant came to be known as flash, which became the accepted name for the vocabulary during the convict period in New South Wales, from 1788 to 1850.
The colonial flash language has had a long journey, affected by the complex socio-cultural changes in the penal settlement in the nineteenth-century arising from increasing economic prosperity, gradual shifts in demographic composition and attitudes, and major events and disruptions like the end of transportation and the gold rush provided constantly changing backdrops impacting its use and transformation.
From the sixteenth-century flash was referred to as ‘pedlars' French'. By the late eighteenth-century it was sometimes called the ‘kiddy language’, and by the early nineteenth-century as ‘St. Giles's Greek’.