Oxford Advanced Learner's Dictionary by A. S. Hornby and Albert Sydney Hornby (2000, Paperback)

This is a "learner's dictionary" in every sense of the words. I had the opportunity to use one of the much earlier editions about 50 years ago. This dictionary was of great help to me in the study of English and its usage. Thanks to the insight of Mr. A. S. Hornby, the pioneering editor. This same dictionary (of any later edition) is an equally important asset for my U.S. born children, niece and nephew who are in college, high school and elementary school. Among a few other dictionaries at their disposal, be they called reference dictionary, college dictionary, even learner's dictionary or otherwise, this Oxford Advanced Learner's Dictionary has certainly won the ultimate jaw-breaking title! Besides, the 2000 edition is still recent and valid enough for its use and the wealth of standard vocabularies, given the transitory nature of the human language.