Most of this section is populated by a first in medical lexicography: a graveyard. This provides a practical answer to the rhetorical question, What do we do with a word or phrase that has been retired and is no longer in active use? The answer embraced by some medical lexicons, is to retain the term as if its use is ongoing.
Retaining terms that should be retired offers a clear advantage to the dictionary’s publisher, given that culling the “dead wood” would substantially reduce the total number of entries, making the work more timely, but smaller*. I recently picked 12 pages at random from the Dorland’s Illustrated Medical Dictionary, and googled each of the terms that I, as a pathologist with over three decades of experience in medical lexicography, felt were no longer in use; 38 fell in this category.†
*Many people who buy dictionaries base their decision of whether to buy Dictionary A or Dictionary B solely on size (number of entries). †The 38 obsolete terms included such dinosaurs as Bozicevich test, chorioblastosis, erythrocytorrhexis, erythrogen, homoglandular, metalloscopy, Enroth sign, Goldstein sign, stethocyrtograph, and stethometry, for an average of 3.2 words/phrases per page. My criteria for suggesting that a term be retired are (1) non-use, based on a low number of “hits” (less than 30) when googled, and (2) the hits are in secondary–e.g., dictionaries or non-peered reviewed work or non-English language literature.
Why are these terms still in? Cost is probably the main driver of the decision to retain a term. Writing definitions is time consuming and quite likely expensive*.
*The following calculation is speculative and makes several assumptions. In the five years between editions of the Dorland’s, the staff (of I believe 4 lexicographers) adds 5000 terms = 1000 terms/year which, divided by 4 (lexicographers), translates to 250 terms defined per year by each of 4 lexicographers, or one new term defined per person per 8-hour day. If we assume that the average lexicographer earns $12.50/hour—the chief would earn more, staffers less—then each definition would cost the publisher about $100. Replacing the 3.2 “corpse terms” on each page, multiplied by 2097 (number of pages in the Dorland’s) = 6710 (number of “corpse terms”) which, multiplied by $100 (cost per term), would set a publisher back nearly $700,000…a seemingly high price for keeping a work up to date, especially one for which the sales are falling year-on-year, which has occurred for the past decade in information products such as dictionaries.
Arguably the most practical solution to this problem is what’s being done in the Modern Medical Dictionary (MMD) database. The obsolete term–e.g., ionprotein is defined–A protein molecule combined with an inorganic ion, with a comment related to minimal use—This term got 79 hits on 03.05.2016, most in secondary and non-English language literature. References in primary literature hover around the turn of the 20th century. With such warnings in place, it seems likely that the reader would choose another word or phrase.
I don’t believe that obsolete terms should be part of a dictionary’s “head count”. The MMD database is built in such a way as to easily flag the 15,000 “corpse terms” and delete them from the final count of terminology. The current total number of terms in the database is, as of the moment (25 April 2017) is 191,778. If we subtract the abbreviations and acronyms (19,500-ish) and corpse terms (15,000-ish), the MMD database has 157,000-ish terms defined.
Also included in this section are terms from anthropology, evolution, based on the fact that like the above “graveyard”, both deal with the past.