The Oxford English Dictionary (OED) is a dictionary published by the Oxford University Press (OUP), and is the most successful dictionary of the English language, (not to be confused with the one-volume Oxford Dictionary of English, formerly New Oxford Dictionary of English, of 1998.) As of 30 November 2005 OED included about 301,100 main entries, comprising more than 350 million printed characters. Additional to the headwords of main entries, it has 157,000 combinations and derivatives in bold type, and 169,000 phrases and combinations in bold italic type, a total of 616,500 word-forms. It has 137,000 pronunciations, 249,300 etymologies, 577,000 cross-references, and 2,412,400 illustrative quotations. The latest, complete printed edition of the dictionary (Second Edition, 1989) was 20 volumes, comprising 21,730 pages, with 291,500 entries.
The policy of the OED is to attempt recording a word's most known uses and variants in all varieties of English, worldwide, past, and present; per the 1933 Preface: The aim of this Dictionary is to present in alphabetical series the words that have formed the English vocabulary from the time of the earliest recordsA.D. 740] down to the present day, with all the relevant facts concerning their form, sense-history, pronunciation, and etymology. It embraces not only the standard language of literature and conversation, whether current at the moment, or obsolete, or archaic, but also the main technical vocabulary, and a large measure of dialectal usage and slang.
The OED is the origin of much scholarly work about English words. Its choice of order in listing variant spellings of headwords influences the written English of many countries.