Oxford Reference Online
Over 100 full text language and subject dictionaries and reference works. Topics covered include general reference, language, science and medicine, humanities, social sciences, and business.
Oxford English Dictionary
Widely acknowledged to be the most authoritative and comprehensive dictionary of English in the world, the OED is the definitive record of English language development over the last fifteen hundred years. It traces the evolution of words through millions of quotations, and includes etymological analysis, variant spellings and pronunciation guides.