The word "slang," first recorded in the mid-18th century, is of uncertain origin: suggestions include the old name for a convict's fetters, the Old Norse verb "to sling," slyngva, and the name of an 18th-century Dutchman, the Lord of Slangenburg. It's an appropriate muddle. Slang initially meant the opaque private diction of criminals, only later expanding to its present sense of any very informal, non-standard language, and it remains a field in which meanings are hard to trace or pin down.
That's not for want of trying, however. Around 1536, some 70 years before the first recognised English dictionary (Robert Cawdrey's Table Alphabeticall), a former apprentice of Caxton's, Robert Copland, published a poem entitled The hye way to the spyttell hous. It consists of a dialogue between the author and a porter at St Bartholomew's Hospital, and deploys with relish the "thieves' cant" of its day: a private vocabulary which included such delights as "pek my jere" (eat excrement), "docked the dell" (deflowered the girl) and "maimed nace" (helplessly drunk). Copland's glossary of "canting words" was Britain's first glimpse of what an English dictionary might look like.
After Copland, it seems, the public could not get enough of cant. Guides to "low" speech proliferated throughout the 16th and 17th centuries—monuments to our delight in coining new words for those eternal human preoccupations: bodily functions, reproduction and intoxication. And those thinking that the increasingly comprehensive "proper" dictionaries of the last few centuries have defeated the demand for such things should think again. Look at the urban dictionary online if you don't believe me. In a digital world, it's the authorities who are on the back foot. We're heading back to Copland.
