100 years after its first publication, the twelfth edition of this world-famous bestseller gives the most up-to-date picture of the English language today. This centenary edition gives rich authoritative coverage of English as it is used today. It features over 240,000 words, phrases, and definitions, covering technical and scientific vocabulary as well as English from around the world. Hundreds of new words and phrases, based on the latest research from the Oxford English Corpus, are included in this edition. Usage notes on tricky vocabulary and grammar usage are also given.