Book excerpt: With its unparalleled coverage of English slang of all types (from 18th-century cant to contemporary gay slang), and its uncluttered editorial apparatus, Cassell's Dictionary of Slang was warmly received when its first edition appeared in 1998. 'Brilliant.' said Mark Lawson on BBC2's The Late Review; 'This is a terrific piece of work - learned, entertaining, funny, stimulating' said Jonathan Meades in The Evening Standard.But now the world's best single-volume dictionary of English slang is about to get even better. Jonathon Green has spent the last seven years on a vast project: to research in depth the English slang vocabulary and to hunt down and record written instances of the use of as many slang words as possible. This has entailed trawling through more than 4000 books - plus song lyrics, TV and movie scripts, and many newspapers and magazines - for relevant material. The research has thrown up some fascinating results