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 half a million words, both present and past. It traces the usage of words through 2.5 million quotations from a wide range of international English language sources, from classic literature and specialist periodicals to film scripts and cookery books.

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 half a million words, both present and past. It traces the usage of words through 2.5 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.

As the OED is a historical dictionary, its entry structure is very different from that of a dictionary of current English, in which only present-day senses are covered, and in which the most common meanings or senses are described first. For each word in the OED, the various groupings of senses are dealt with in chronological order according to the quotation evidence, i.e. the senses with the earliest quotations appear first, and the senses which have developed more recently appear further down the entry. In a complex entry with many strands, the development over time can be seen in a structure with several branches .