The Oxford English Dictionary (OED) was born in 1857 when the Philological Society of London determined that a substantial and thorough dictionary of the English language did not exist. The Society decided to set to work on a historical dictionary which would trace the roots of the English language, and include archaic words and meanings which were no longer in use. The project, today known as the OED, is widely recognized as the most comprehensive English dictionary in existence.
The OED should not be confused with a conventional dictionary. Most dictionaries include the most recent meaning of a word, along with a pronunciation guide. An OED entry starts by listing the word, alternate spellings, and current pronunciation along with all current definitions.
Here the similarities end. The entry goes on to trace the word, indicating when it was first introduced to the English language, how the meaning of the word has changed, and the etymology of the word. The OED covers words in use as far back as Middle English, and some entries are for words which are far older, although the meaning of the word has since changed. All entries are supported by quotations, which are painstakingly hand gathered from hundreds of years of English literature.
The OED took a long time to get off the ground. Although it was determined in 1857 that such an undertaking needed to commence, an editor was not contracted until 1879, when James Murray was brought on board. It was estimated that the complete project would take 10 years, and comprise four volumes. The project actually took 70 years, going through multiple editors, and encompassed 10 volumes. Volumes of the OED were released individually to the eagerly waiting academic public, with the first being published in 1884.
The First Edition of the OED was finished in 1928. Five years later, a supplement to the dictionary was published. Because English is a living language, the dictionary requires constant revision in order to remain current and accurate. A second supplement was released between 1972-1986, and a great deal of time was invested in modernizing the OED in the 1980s, when the entries began to be converted to a computer database. In 1989, the Second and most recent edition was published, followed by a CD-ROM version of the OED in 1992. A Third Edition is underway, although the publication date is uncertain.
The Second Edition of the OED, published in 1989, contains 291,500 entries. Most of the entries detail multiple meanings of a word, with the longest entry being for the word “set,” which includes 430 senses or uses of the word. A complete Second Edition OED weighs 151 pounds (68 kilograms) in 20 volumes. A smaller version, known as the Compact OED, is available, and consists of two volumes of extremely dense text, weighing in at 15 pounds (6 kilograms).