At the graduate level, you will not be helped much by “college” and “school” dictionaries, such as those published by Cassell’s, Bantam, and Collins. These are fine if what you need is a portable glossary of Classical Latin, but they do not provide the range of vocabulary or the detailed information about usage that you will need for studying medieval Latin texts.

Time periods covered by various Latin dictionaries

The following table allows comparison of the chronological range, by centuries BCE and CE, of sources on which various excellent Latin dictionaries are based. Links will take you to the description of each dictionary below.

Dictionaries for daily use

Lewis & Short

A few of the copies of “Lewis & Short” in the PIMS Library.

If you are going to have only one Latin dictionary, the best one to have for reading medieval Latin is “Lewis and Short,” which originally appeared in identical forms under two different titles:

• Harper’s Latin Dictionary (New York: American Book Company, 1879)
• A Latin Dictionary (Oxford: Clarendon Press, 1879)

It has been in print continuously ever since, and new copies can still be acquired from Oxford University Press. Less expensive used copies often turn up in the inventories of online and bricks-and-mortar used book sellers.

It has also, of course, been completely digitized. Not only is Lewis and Short searchable through websites and smartphone apps, it has also been fully integrated into several databases and other digital tools, such as the Perseus Latin Word Study Tool.

Lewis and Short only includes headwords and citations from Classical and Late Latin authors down to ca. 600 CE., which means that some distinctively “medieval” words and usages are not covered. Furthermore, it is marred by errors and oversights that have long been lamented and lampooned by Classical scholars.¹ But for medievalists, there is simply no other one-volume dictionary that comes close to Lewis and Short for range and versatility.

“Smith’s Smaller”

An evidently much-used copy of “Smith’s Smaller”	Reborn in paperback and still in print as the Chambers Murray Latin-English Dictionary

For quick reading reference, or to keep in your backpack for consultation when riding the TTC, you might find it convenient to use the following, which is my favourite “hand-sized” dictionary. Like Lewis and Short, it too can be found in two (identical) forms:

• William Smith and John Lockwood, A Smaller Latin-English Dictionary, 3rd edn (London: Murray, 1933; various unaltered in reprints with later dates).
• Reprinted as the Chambers Murray Latin-English Dictionary (Edinburgh: Chambers; London: John Murray, 1976; most recent reprint 2001)

“Smith’s Smaller” is more restricted in range than Lewis and Short, covering only select Classical authors down to Ausonius (d. 390 CE). But it’s more than adequate for general use, and what makes it especially valuable is that it puts macrons over all long vowels, including the “hidden” ones that are not marked in Lewis & Short.

Oxford Latin Dictionary (OLD)

Oxford Latin Dictionary, ed. P. G. W. Glare (Oxford: Clarendon Press, issued in fascicles 1968–1983; 2nd edn, 2 vols., 2012). This one isn’t usually of much interest to medievalists, but it’s essential for those studying Latin from its origins down to ca. 200 CE. It has enjoyed a mixed reception. See, for example, this (in)famous review of the first edition by F. R. D. Goodyear.

There is no “official” online version of the OLD. A scan of the first edition (completed in 1983) can be consulted at the Internet Archive.

The second edition of the OLD (2012), however, is built into the “back end” of Oxford Scholarly Editions Online, to which students and professors at universities often have institutional access. If you open up the OSEO version of a work by any Latin author, there will be a column at the righthand side containing links to OLD entries on Latin words in the edited text. If you click on one of these, a pop-up widget will appear. The widget will show you the entry for that word in the OLD, but it will also have a search box into which you can enter any word to see its entry. You might bookmark the OSEO edition of Cicero’s Brutus, for example, and use it as your access point.

Dictionaries for research work

Thesaurus Linguae Latinae (ThLL)

ThLL on the shelves in the PIMS Library.	Some of the boxes containing handwritten slips that make up the “materia” of the ThLL.

The Thesaurus Linguae Latinae (ThLL)is the heavy of heavies. What the Oxford English Dictionary is for English, the ThLL is for Latin, from the earliest evidence down to ca. 600 CE. And just as the OED is a dictionary of English that is written in English, so the ThLL is a dictionary of Latin written in Latin. (See the pages About the TLL at the project website.)

Many of the articles include references to every single occurrence of the word in question in the whole corpus surveyed. (An asterisk before a word means that the article does not give this complete coverage.) If you are trying to pin down the usage of a word in a difficult passage, the ThLL will clearly lay out the various possibilities and supply you with ample examples with which you can compare your own text.

Completion of the whole dictionary is not expected before 2050. The published volumes covering A–nemus and O–relinquus can be consulted freely online. It is expected that those covering relinquo–resilio will be put online sometime next year.

Alexander Souter, Glossary of Later Latin to 600 A.D.

This little glossary can be used as a supplement and corrective to Lewis and Short for words attested after the cutoff date of the Oxford Latin Dictionary (i.e., after ca. 200, down to ca. 600). Souter was the original editor of the OLD, and he seems to have been a rather demanding and difficult character! But he was a very diligent discoverer of “new” words that had been missed in earlier dictionaries.

Albert Blaise, Dictionnaire latin-français des auteurs chrétiens, rev. Antoine Dumas (1954)

For those who work on the Vulgate Bible and Christian authors, from the origins of Christianity down as far as authors writing in the eighth century, this dictionary is indispensable.

The only downside is that the French definitions are sometimes conveying shades of nuance that cannot be appreciated by an English-speaker without the aid of a “big” French-English dictionary, such as J. E. Mansion, Harrap’s New Standard French and English Dictionary, part 1: French–English, rev. and ed. R. P. L. Ledésert and Margaret Ledésert, 2 vols. (London: Harrap, 1972).

Albert Blaise, Lexicon latinitatis medii aevi (1975)

Albert Blaise’s Lexicon Latinitatis medii aevi praesertim ad res ecclesiasticas investigandas pertinens / Dictionnaire latin-français des auteurs du Moyen-Âge (1975) second dictionary covers only words and usages for the period ca. 600–ca. 1500 that he did not cover in his 1954 Dictionnaire des auteurs chrétiens. The two must therefore be used in tandem. As the Latin version of the title says, it primarily covers the vocabulary of ecclesiastical sources.

J. F. Niermeyer, Mediae Latinitatis lexicon minus

For work on non-ecclesiastical medieval sources, the counterpart to Blaise is Niermeyer, here shown in its revised second edition (2 vols., 2002). Niermeyer covers mainly narrative, legal, and documentary sources for the period ca. 600–ca. 1200. Each entry has glosses and explanations in three languages (English, French, and German), which makes it a very popular and useful resource.

Du Cange, Glossarium Mediae et Infimae Latinitatis

Novum Glossarium Mediae Latinitatis (NGML)

Dictionary of Medieval Latin from British Sources (DMLBS)

1. You will very often see references to the “mistakes” or “unreliability” of Lewis and Short, but it’s harder to find a convenient list of these. One very interesting resource is Henry Nettleship, Contributions to Latin Lexicography (Oxford: Clarendon Press, 1889). [Internet Archive] Nettleship had been commissioned to produce a new Latin dictionary for Oxford University Press, but when, after over ten years, he had received none of the help that had been promised to him, the press suggested that he instead give them a book of “additions to, or improvements upon, what may be found in current Latin dictionaries.” In the resulting volume, Nettleship said: “I have taken Lewis and Short’s Dictionary as my basis; and have published nothing which I do not, on full consideration, deem to be a necessary improvement upon that work” (p. vii). For example, under usage 1 of Ā, ăb, abs (“In the local sense of on the side of“), Nettleship quotes Caesar’s De bello Gallico 2.25.1: “quidam a novissimis,” adding in parentheses, “wrongly explained by Lewis and Short as = ex novissimis.” ↩︎