gives this genealogy of "cant":

"insincere talk," 1709, earlier it was slang for "whining of beggars" (1640s), from a verb in this sense (1560s), from O.N.Fr. canter (O.Fr. chanter) "to sing, chant," from L. cantare, frequentative of canere "to sing" (see chant). Sense in English developed after 1680 to mean the jargon of criminals and vagabonds, thence applied contemptuously by any sect or school to the phraseology of its rival.

The OED tracks "cant" to the 1300s and 1400s when it served all kinds of noun-verb-adjective duties: an edge, a brink, a musical sound, begging, an auction, a share or division, a trick or illusion, lively and hale, to apportion, to mend, etc.

I bring it up because of these few paragraphs from a recent article in the Telegraph by Mark Forsyth.

It's about the French press's linguistic reaction to an incident in the Tour de France, when someone scattered tacks on the road and British cyclist Bradley Wiggins sportingly stopped to let his delayed competitors catch up. But the most interesting stuff comes later in the piece:

Few people read dictionaries cover to cover, and you get rather odd looks if you do. Lately, in the course of researching a new book on the lost words of the English language, I’ve been devouring them, and it’s astonishing how much they can teach you about the lives of others.

For example, histories of the Second World War will tell you all about a soldier’s experience of D-Day, but you must remember the old adage that war is 1 per cent terror and 99 per cent boredom. If you want to know what a soldier’s life was really like in the Forties, pick up a dictionary of Services slang. Most of the words have nothing to do with fighting: they’re to do with gossiping, making tea, and waiting around. There were furphies (gossip started in the lavatories), and elsan gen (gossip so obviously false it was fit only to be flushed down an Elsan lavatory). There was duff gen, pukka gen, and the gen king (who knew all the gossip). Only very occasionally do you get even the faintest hint of death and glory.

Still, if it is death you want, you should turn to dictionaries of cant – the thieves’ and highwaymen’s slang of the 17th and 18th centuries. At a time when hanging was the punishment for even petty crime, highwaymen had a thousand euphemisms for the place they might end up. When the trapdoor opened they were left “dancing on nothing”, a dawn execution was “having a hearty-choke and caper sauce for breakfast”, where the caper again refers to the twitching feet of the hanged man. You also get fascinating glimpses into their sex lives: the number of terms and fine distinctions between different types of prostitute is enough to make a cinqasept [French slang for visiting one's mistress in the late afternoon] seem positively tame...

[In] 19th-century Roxburgh, they had a single word – sprunt – meaning to run after girls among the haystacks after dark.

Roxburgh was in Scotland... I wonder if "sprunt" somehow derives from "sprint after cunt"? It's linguistically possible—"sprint" was around in the 19th century and the OED has traced "cunt" to a 1230 compendium of street names in London, including "Gropecuntelane," which sounds like a lively street on a 13th-century Saturday night.