The American Heritage Dictionary of the English Language
The American Heritage Dictionary of the English Language (AHD) is an American dictionary of the English language published by Boston publisher Houghton Mifflin, the first edition of which appeared in 1969. Its creation was spurred by the controversy over the Webster's Third New International Dictionary.
James Parton, the owner of the history magazine American Heritage, was appalled by the permissiveness of Webster's Third, published in 1961, and tried to buy the G. and C. Merriam Company so he could undo the changes. When that failed, he contracted with Houghton to publish a new dictionary. The AHD was edited by William Morris and relied on a usage panel of 105 writers, speakers, and eminent persons chosen for their well-known conservatism in the use of language. However, Morris made inconsistent use of the panels, often ignoring their advice and inserting his own opinions.
The AHD broke ground among dictionaries by using corpus linguistics for compiling word-frequencies and other information. It took the innovative step of combining prescriptive information (how language should be used) and descriptive information (how it actually is used). The descriptive information was derived from actual texts.
Usage panel 
For expert consultation on words or constructions whose usage is controversial or problematic, the American Heritage Dictionary relies on the advice of a usage panel. In its current form, the panel consists of 200 prominent members of professions whose work demands sensitivity to language. Present and former members of the usage panel include novelists (Isaac Asimov, Barbara Kingsolver, David Foster Wallace, and Eudora Welty), poets (Rita Dove, Galway Kinnell, Mary Oliver, and Robert Pinsky) playwrights (Terrence McNally and Marsha Norman), journalists (Liane Hansen and Susan Stamberg), literary critics (Harold Bloom), columnists and commentators (William F. Buckley, Jr., and Robert J. Samuelson), linguists and cognitive scientists (Steven Pinker and Calvert Watkins), and humorists (Garrison Keillor, David Sedaris, and Alison Bechdel).
The members of the panel are sent regular ballots asking about matters of usage; the completed ballots are returned and tabulated, and the results form the basis for special usage notes appended to the relevant dictionary entries. In many cases, these notes not only report the percentage of panelists who consider a given usage or construction to be acceptable, but will also report the results from balloting of the same question in past decades, to give a clearer sense of how the language changes over time.
The AHD is also somewhat innovative in its liberal use of photographic illustrations, which at the time was highly unusual for general reference dictionaries, many of which went largely or completely unillustrated. It also has an unusually large number of biographical entries for notable persons.
First edition 
The first edition appeared in 1969, highly praised for its Indo-European etymologies. In addition to the normally expected etymologies, which for instance trace the word ambiguous to a Proto-Indo-European root ag-, meaning "to drive," the appendices included a seven-page article by Professor Calvert Watkins entitled "Indo-European and the Indo-Europeans" and "Indo-European Roots", 46 pages of entries that are each organized around one of some thousand Proto-Indo-European roots and the English words of the AHD that are understood to have evolved from them. These entries might be called "reverse etymologies": the ag- entry there, for instance, lists 49 terms derived from it, words as diverse as agent, essay, purge, stratagem, ambassador, axiom, and pellagra, along with information about varying routes through intermediate transformations on the way to the contemporary words.
Second and later editions 
The second edition, published in 1980, omitted the Indo-European etymologies, but they were reintroduced in the third edition, published in 1992. The third edition was also a departure for the publisher because it was developed in a database, which facilitated the use of the linguistic data for other applications, such as electronic dictionaries.
The fourth edition (2000) added Semitic language materials, such as an analogous appendix of roots, and included color illustrations. It is larger than the desk dictionaries of the time but smaller than Webster's Third New International Dictionary or The Random House Dictionary of the English Language. There is a lower-priced college edition with monocolor printing.
The AHD has a long tradition of inserting minor revisions (such as a biographical entry, with photograph, for each newly elected U.S. President) in successive printings of any given edition.
The most recent edition, the Fifth Edition, was published in November 2011.
See also 
- Pronunciation respelling for English, which compares the pronunciation respelling scheme of the AHD with other dictionaries.
- John Ottenhoff, "The perils of prescriptivism: Usage notes and the American heritage dictionary," American Speech, Fall 1996, Vol. 71 Issue 3, p272-85
- The American Heritage Dictionary of the English Language, Fifth Edition.
- Official website
- Members of the Usage Panel
- American Heritage Dictionary of the English Language online
- The American Heritage Dictionary Software
- Boston Globe review of the AHD 3rd edition (1992)