Oxford English Dictionary Online
The Oxford English Dictionary is the accepted authority on the evolution of the English language over the last millennium. It is an unsurpassed guide to the meaning, history, and pronunciation of over 600,000 words, both present and past. It traces the usage of words through 3 million quotations from a wide range of international English language sources, from classic literature and specialist periodicals to film scripts and cookery books.
The OED covers words from across the English-speaking world, from North America to South Africa, from Australia and New Zealand to the Caribbean. It also offers the best in etymological analysis and in listing of variant spellings, and it shows pronunciation using the International Phonetic Alphabet.