Oxford English Dictionary (OED) Online
The Oxford English Dictionary (OED) is widely regarded as the accepted authority on the English language. It is an unsurpassed guide to the meaning, history, and pronunciation of 600,000 words— past and present—from across the English-speaking world.
As a historical dictionary, the OED is very different from Dictionaries of current English, in which the focus is on present-day meanings. You’ll still find present-day meanings in the OED, but you’ll also find the history of individual words, and of the language—traced through 3 million quotations, from classic literature and specialist periodicals to film scripts and cookery books.