Whenever I had a query about slang (and I’ve had many), or felt like a random trawl through the underbelly of language (which was often), my first port of call, traditionally, was Chambers Dictionary of Slang by Jonathon Green. I have several slang dictionaries for various countries or lexical domains, but CDoS was the most generally useful. It has since been superseded: instead of CDoS I now turn to GDoS.
Green’s Dictionary of Slang is the culmination of a life’s work for Green. First published in print as a three-volume behemoth in 2010, to awards and rave reviews, it now emerges in digital form with about 30% ‘revised, augmented and generally improved’. I’ve been beta-testing the website and can report it is a beautiful thing, vast and wondrous, filthy and fabulous, endlessly diverting and eye-opening.