When faced with a rare or unfamiliar Latin word, medievalists have no single lexicon to turn to. Instead, the best practice is usually to follow a trail of authorities, one that typically begins with Lewis and Short, Blaise, Du Cange, and Niermeyer, before branching off to more recent general dictionaries (e.g., the Mittellateinisches Wörterbuch--currently on the letter 'H'--and the Novum Glossarium Mediae Latinitatis--which began with 'L' and is currently on 'P') and dictionaries defined by region. One of the most successful of the many national dictionaries of Medieval Latin undertaken in the last hundred years is the Dictionary of Medieval Latin from British Sources, of which the fascicule under review represents the second-to-last volume.
The origins of the Dictionary of Medieval Latin from British Sources date back to 1913, the year in which R.J. Whitwell submitted a proposal to the British Academy for a dictionary of Medieval Latin to partially replace the venerable Glossarium ad scriptores mediae et infimae Latinitatis compiled by Charles Du Fresne, Sieur Du Cange in 1678 (and updated thereafter). In 1924, the British Academy established committees to gather material for a dictionary of Medieval Latin as used in the British Isles. The result was the Medieval Latin Word-List from British and Irish Sources, published in 1934, and its updated version, the Revised Medieval Latin Word-List from British and Irish Sources, edited by R.E. Latham, which appeared in 1965. After the appearance of the latter volume, a new committee was established to oversee the production of a dictionary proper, and Latham was appointed as the first editor. The first fascicule of the Dictionary of Medieval Latin from British Sources was published in 1975. Latham was replaced as editor by David Howlett in 1979, and Howlett was succeeded by Richard Ashdowne in 2011. Almost all of the volume under review was prepared under Howlett's supervision. The final fascicule of the dictionary was published in December of 2013, bringing a project some ninety years in the making to completion. 
The DMLBS covers a wide chronological scope, beginning with Gildas in the mid-sixth century and going down to the end of the sixteenth century. The editors wisely took a maximalist approach in deciding what would fall under the heading of 'British' sources, so that the DMLBS includes not only English, Scottish, and Welsh authors writing on their native soil, but British authors abroad (e.g., Alcuin), and authors writing in territories held by the English crown (e.g., Normandy after 1066). Because the Dictionary covers a wide array of authors and spans over a millennium, users are advised to pay careful attention to the sources from which definitions are drawn. The first fascicule contained a list of the sources used to compile the dictionary. A revised version of this list was published in the third fascicule, and some further revisions were made in fascicule six. Users can also consult the very handy on-line bibliography at http://www.dmlbs.ox.ac.uk/sites/default/files/DMLBS%20Bibliography.htm.
Reviewing a single fascicule of a lexicon is not easy, but two features of this and the other volumes of the DMLBS warrant particular notice: the presence of 'hermeneutic' or 'glossematic' vocabulary (i.e., words chosen for their obscurity and difficulty), and the large number of words that entered into Latin from the vernaculars used in the British Isles (Anglo-Saxon, Middle English, Welsh, Anglo-Norman, Norse, etc.). Some forty years ago, Michael Lapidge expressed the wish that the DMLBS would "provide an essential tool for the study of the hermeneutic style in Anglo-Latinity."  Happily, his wish has been realized, and a number of the hermeneutic words identified in his work appear in this volume. The reader will find the meaning of such obscure Grecisms as scanosis ('numbness, torpor'), senpecta ('elder brother, senior monk'), and scirros ('hardened swelling, tumor'), as well as other abstruse lexical items. This fascicule is also characterized by the heavy contribution of loan-words from vernacular languages. Some of these will be readily intelligible to English speakers, e.g., samitum ('samite'); skirmagium ('skirmish'). Other meanings will be less obvious, e.g., sanappa ('runner, napkin, towel,'); skela ('vessel, bucket, bowl, pan'); skeppa ('basket, hamper').
The dictionary is easy to use and attractively formatted; one can learn a great deal from simply perusing individual fascicules at random. The Dictionary of Medieval Latin from British Sources has proven itself to be an indispensable resource, not only to those working on British sources, but to any student of Medieval Latin, and the completion of the dictionary should be welcomed by all medievalists.
1. See R. Ashdowne, "ut Latine minus vulgariter magis loquamur: the making of the Dictionary of Medieval Latin from British Sources," in Classical Dictionaries, Past, Present and Future, ed. C. Stray (London: Duckworth, 2010), 195-222.
2. Michael Lapidge, "The Hermeneutic Style in Tenth-Century Anglo-Latin Literature," Anglo-Saxon England 4 (1975): 67-111.