The Cambridge Dictionary of American English describes the ways American English is used now -- what words mean, how they are pronounced, their usual grammatical behavior, and typical contexts in which they appear. It was written using the Cambridge International Corpus, a computerized collection that includes some 100 million words of written and spoken American English taken from recent books, magazines, newspapers, radio and television broadcasts, and even telephone conversations. This resource provides substantial evidence of how words are used, which allows dictionary writers to describe the language accurately and to give examples that are based on genuine, present-day writing and speech.

This dictionary has a number of features that make it a very user-friendly dictionary: guidewords help you find the meaning of a word you are looking for; language portraits explain the complexities of English, from "Addresses" to "Zero"; idioms and compounds are defined within the entry for their first important word; the idioms index helps you find an idiom even if you only can remember part of it; usage labels tell you when a word is appropriate, and when it is not; and usage notes give additional information about a word.