Lexicographer Jonathon Green selects the slang words and expressions that encapsulate the age in which they were coined.
I've been collecting slang and and publishing books about it for 30 years. My database contains 125,000 words and phrases and they keep coming.
One thing I've learnt - the more slang changes, to half-inch the well-known phrase, the more slang stays the same.
Politically correct, even polite: I fear not. But humanity at its most human, absolutely.
As examples I offer a selection of terms that display some of slang's nuts and bolts:
http://www.bbc.co.uk/news/magazine-27405988