The New Oxford American Dictionary is the most accurate and richly descriptive picture of American English ever offered in any dictionary. Oxford's American editors drew on a 200-million-word databank of contemporary North American English, plus the unrivaled citation files of the world-renowned Oxford English Dictionary.
Fully updated in 2010, this is the most comprehensive and up-to-date American English reference.
350 000 words, phrases, and senses
70 000 audio pronunciations from the Oxford Sound Bank
75 000 usage examples
35 000 etymologies
Includes word list of over 270 000 entries for word finding and use with Crossword Compiler
The download size is about 130MB (you can also order a CD-ROM).