Rational for changes: the terminology refers to these fortified buildings changed over time. At Vicipaedia we prefer the more ancient term, as the page name, so I have arranged the above pages based on the information at L&S. Further explanation:
arx = citadel (a kind of castle or defense overlooking a city)
castle = castellum (redoubt) = burgus (medieval castle) = pugnaculum (fortified defensive structure) ( hardly find any difference between burgus and burgus medievalis that couldn't be explained on a single page)
fort = castrum [1] = propunaculum (the favored 16-18th century translation of fort, for example seen in many sources, most significantly including [2]), however in general it seems to mean bulwark or rampart
Castra (res militaris) = military camp, as a terminus technicus, it deserves it's own page. = praesidium (a military base or garrison associated with a city or fort.
After seeing the en.wiki has separate articles for each concept, I'd like to propose doing the same rather than what I proposed above.Thus I propose the below (english page to be referenced in parenthesis)--Rafaelgarcia22:40, 18 Iulii 2009 (UTC)Reply
I added a couple of more entries to reflect en.wiki's topic list. Last but not least I propose we change the name of this formula to munimen (=munimentum) but is shorter.--Rafaelgarcia05:04, 19 Iulii 2009 (UTC)Reply
Since some of these terms shade into one another, drawing bright lines among them might be overly restrictive. A citadel, according to MWCD, is 'a fortress that commands a city'; but what about a fortress that commands a city by means of commanding its harbor, like Fort Sumter (Charleston) and Fort Pulaski (Savannah)? ¶ Also, you'll probably want to include armamentarium 'armory'. ¶ Also, especially for the United States, don't forget to find a Latin term for 'camp', which refers to a permanent installation, sometimes huge (many square miles), that doesn't have three requisites of a Roman castra, an agger, a fossa, and a vallum ; for example, Camp Lejeune & Camp Pendelton. An American camp may be practically indistinguishable from certain forts (e.g., Fort Bragg)—and both camps & forts (and other military installations) may be bases. ¶ Also, there's the modern term bivouac.IacobusAmor11:38, 19 Iulii 2009 (UTC)Reply
Murus was the term also for an extended defensive barrier like Hadrian's Wall (Historia Augusta "Hadrian" 11.2; Gildas 15.3; etc.). I can't find authority for the word vallum in this case (in spite of Vallum Aelium suggested in the en:wiki article, Vallum Hadriani adopted in some other wikis); hence it was right, I think, not to adopt "vallum Maginot". Andrew Dalby (disputatio) 12:06, 19 Iulii 2009 (UTC)Reply
Cassell's says a vallum is (basically) 'a palisade made from stakes and set up on a rampart', and (in a transferred sense) 'a fortification, defence'. IacobusAmor13:10, 19 Iulii 2009 (UTC)Reply
For the Vallum Hadriani, I found references and explanations in a Google Book. The term Vallum Hadriani apparently is OK as a name since there were two walls that ran more or less parallel to each other: a wooden one (vallum) and a stone one (murus). It is controversial if the vallum was built first or if they were built simultaneously.
You're right about Murus it is the proper term for any stone wall in general--this includes most moenia (defensive city wall, rampart, which do not all have to be stone), garden wall, building wall. It's unfortunate that the english page named defensive wall is more about rampart and city walls than about
The blurrings, secondary meanings, and all synonyms should be explained under the appropriate articles in an etymology or history section or paragraph. However, I tried very hard to keep the primary sense of the terms as the page names.
From my investigation, the blurring of the terms came about because for example a castellum intially a small fort or redoubt (castellum) or watchtower (burgus) later turned into a full blown castle and keep, a castrum became a city, etc.. but the names were preserved as reminding people how the place started.
For propugnaculum, for example, the blurring occured because the nature of an 16-18th century fort was more of a rampart than the ancient Roman castrum would suggest and also people tried to avoid falling into the trap of the terminus technicus castra plural meaning camp.
For translating Camp in e.g. Camp Lejune I definitely think it should be Castrum. As noted above, a castrum definitely evolved beyond the ancient castra and today can emcompass a permanent extended military base, without any ramparts, bulwarks or other earthen defenses. What I proposed above is to leave the term "castra" with the ancient Roman meaning of Caesar's time, but under the term Castrum to explain the millenia of evolution of the military camp.
All castra and castella started as temporary camps, but as the empire evolved they remained in place for decades and became permanent and as big as cities. When they stayed in place for more than a few years, the custom of the Romans was to build stone walls, with gates and stone towers, just like regular walled cities and castles. For this reason by the time of the vulgate castrum and castella had become popular synonyms for city and town in many parts of the empire. --Rafaelgarcia14:57, 19 Iulii 2009 (UTC)Reply
The nature of a citadel (=arx, acropolis) is explained in the english page en:citadel. From what is said there it would not be appropriate to call it a arx/citadel except in a derived figurative sense. Fort Sumter satisfies the idea of protecting the city (from ocean attack by indirectly commanding the entrance to the harbor) but it does not command the city (you can hardly see it from the city), the citizens would not ever have been able to flee there, nor could it directly protect the city. Furthermore, arx as a term does not translate fort at all.--Rafaelgarcia15:23, 19 Iulii 2009 (UTC)Reply
Castrum was suggested as the genus "fortified places" upon the recommendation of Lewis and Short: " In sing., any fortified place". The translation specifically suggested for Fort is Propugnaculum, recommended by Ainsworth and also Francis Glass, American historian.
Your remark about castle is valid. A castellum literally means a small castrum: and a burgus a small castellum. In the original sense, castrum was a full fledged fort, with all its protections and facilities, the castellum (diminutive) a redoubt with a small garrison and outer wall, while a burgus was typically just a tower like fortification. As these structures attained stone walls, and other medieval muniments they became what we call in english "castles" in the most general sense.
There is no one latin term that I can find for "castle" that covers the full range from burgus to castrum, other than castrum in the primary, most general sense given by L&S, but this term covers every other fortification out there. In identifying burgus mediaevalis as en:castle, I was following a sentence somewhere that said the burgus is what most people think of when they think of medieval castle. Also Caesar specifically uses the term castellum only in the sense of en:redoubt, so that if one term has to be chosen for redoubt this is it. And also someone else had already linked burgus to en:castle. And Words gives castellum = redoubt and burgus = castle as the primary sense of each term.
Admittedly, there is no single idea of what a castle is, as you can see from the various wikipedia articles on castles. In france and germany, the prototypical late medieval castle as a fortified palacial residence of a king was called a burgus, the name orginating because the burgi originated as residential strongholds. On the other hand, in Britain, the motte and bailey castle was a kind of castellum consisting of an arx and a two valla. In Spain evidently, both burgus and castellum type fortifications exist.
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