Macmillan English Dictionary for Advanced Learners

Collins English Dictionary
By John McHardy Sinclair
This fourth edition contains a wealth of new words and meanings, technical terms and abbreviations, as well as thousands of new and updated biographical and geographical entries.
Collins English Dictionary
By Gerald Alfred Wilkes, William Alwyn Krebs
Collins English Dictionary
Longman Dictionary of Contemporary English
By Michael Mayor
Fully updated for 2009, and with a brand new user-friendly design, this edition is full of exciting new features to help learners become fluent in English, including cutting edge software to build vocabulary faster.