An abridged edition of the world's bestselling original thesaurus. This completely revised and updated edition contains over 230,000 words, nearly three thousand of which are newly added. The revolutionary achievement of Dr. Roget was his development of a brand new principle: the grouping of words according to ideas. If the user cannot find something in a reference book, it is often because of the restriction of searching alphabetically by 'known' headwords. Dr. Roget's thesaurus reversed the access to allow the user to find a word from another word, a concept or an idea.