BBC NEWS | UK | Magazine | Roll over Roget

BBC NEWS | UK | Magazine | Roll over Roget: "The Historical Thesaurus of the Oxford English Dictionary, published by Oxford University Press, is the culmination of 44 years of painstaking work by scholars at the University of Glasgow.

It not only groups words with similar meanings but does so in chronological order according to their history - with the oldest first and most recent last. According to its publisher, the OED, it's the largest thesaurus in the world and the first historical thesaurus in any language.

With 800,000 meanings, 600,000 words and more than 230,000 categories and sub categories, it's twice as big as Roget's version."