The Oxford English Dictionary (OED) is a guide to the meaning, history, and pronunciation of 600,000 words - past and present - from across the English-speaking world. The OED Online also features the Historical Thesaurus of the OED, which arranges the dictionary by meaning.
N.B. The current online version of the OED is derived from the printed second edition of 1989, which is in turn based on the original edition published 1884-1928. The dates of the latest upload are provided for your information. However, bear in mind that not all entries have been fully revised from their original entries (apart from bibliographical standardisation) so it is always worth checking the date information at the foot of the page and the latest date of quotations in the entry to ascertain how old the entry you are viewing may be.
You can view a short online introduction about the OED, with audio commentary, from here
To access this introduction you need to open the Powerpoint presentation and select 'View show' it will then begin automatically
Alternatively you can take a tour of the OED (9MB, PowerPoint Show (.pps) format)
Oxford Reference Online brings together over 175 Quick Reference works published by Oxford University Press into a single cross-searchable resource. The English Dictionaries and Reference section includes regional English dictionaries (Australian, Canadian, New Zealand and American Englishes) and English grammar and usage guides.
You can link to these two sections from here:
If you have not used these resources before, you may find the following guides useful:
Early English Books Online (EEBO) Sample Searches (PDF)
Eighteenth Century Collections Online (ECCO): Basic Search (6 min video)
Eighteenth Century Collections Online (ECCO): Advanced Search (2 min video)
The Middle English Dictionary offers a comprehensive analysis of lexicon and usage for the period 1100-1500. This electronic version of the MED preserves all the details of the print MED, but is searchable in ways impossible within any print dictionary.
The MED is part of the Middle English Compendium, which has been designed to offer easy access to
and interconnectivity between three major Middle English electronic
resources: an electronic version of the Middle English Dictionary, a
HyperBibliography of Middle English prose and verse, based on the MED
bibliographies, and a Corpus of Middle English Prose and Verse, as well
as links to an associated network of electronic resources.
Guidance on how to use the MED can be found here: