I’m acquainted, to varying degrees, with a few translations of Tolkien’s fiction, and I understand the challenges to producing a successful, faithful rendition of his work in another language. Indeed, several books have been written on the subject — if you’re interested in recommendations, drop me a comment. But up to now, my knowledge of these challenges has been at some remove. I’d studied some of the translator’s choices in Lo Hobbit (Italian), mainly in the matter of second-person address, but that was about all. But more recently, I came face to face with another of the thousand little (some, not so little) difficulties in translation. It happened in an unexpected way.
I was thumbing through one of our Italian cookbooks, Italy in Small Bites, a collection of merende of every imaginable variety. Think Italian tapas, and you’re on the right track. Or perhaps amuse-bouches. If you don’t know what any of these are, then I can’t help you. :) Anyway, I came across a delicious-sounding recipe for Zucchine a Fiammifero (“Matchstick Zucchini”). Naturally, as soon as my eyes fell on fiammifero I thought of Bilbo’s Song of Eärendil in The Fellowship of the Ring. The final line of the poem, for those who manage to read the entire thing (!), is “The Flammifer of Westernesse” — and this is Tolkien’s only use of that word. One word out of more than 500,000 — typical of the assiduous thought Tolkien put into every single word choice.
I had probably learned the Italian word fiammifero at one time, but if so, then it never struck this chord until now. Its etymology is pretty obvious, as is the English *flammifer which Tolkien invented for The Lord of the Rings. Both derive from Latin flammifer, meaning “fiery”, from flamma “flame, fire” + ferre “to carry, bring, bear”, thus, “fire-bearing”. Tolkien turned the word into a noun, and of course, the Italian word is a noun as well, but the original Latin word is an adjective, like fātifer “deadly”, sacer “holy”, and another word I daresay most of us know, lūcifer “light-bearing”. This latter is also attested as a noun, and probably provided Tolkien with the clearest linguistic model for his own coinage.
It seems to me that, from a purely philological standpoint, Tolkien might have wanted to use the word lucifer in reference to the Silmaril of Eärendil had it not acquired the negative religious hues that have colored the word since the Middle Ages. I broached this idea in a footnote to my essay in Truths Breathed Through Silver, but so far, I can’t recall that anybody (myself included) has pursued the possibility any further. So, in the event, Tolkien opted for the roughly synonymous flammifer instead. In English, I have found the adjective flammiferous “bringing flame” attested in Thomas Sheridan’s 1780 dictionary, and the OED cites the word from another dictionary a century earlier (though I don’t have an OED to look the citation up).
According to Peter Gilliver, et al., this adjective is the only form attested prior to Tolkien’s invention.  It’s pretty characteristic of Tolkien to resurrect a word like this from the bowels of obscurity. Where did he get it? One possibility is that it was suggested, or recalled to his mind, by lucifer. But there may be another likely source. I personally suspect that Tolkien borrowed it from Ovid. In the Metamorphoses, Book XV, Ovid writes:
[…] luna volat altius illa
flammiferumque trahens spatioso limite crinem
stella micat, natique videns benefacta fatetur
esse suis majora et vinci gaudet ab illo. [ll. 848–51]
The Horace Gregory translation I have on my bookshelf isn’t very literal at all, so I’ll just give you my own translation of the key phrase from the middle of the quotation (with whatever faults attentive readers might wish to point out): “a star sparkles, drawing after it in a spacious track its fiery hair (i.e., the tail of a comet).” The reference is to an actual comet seen in 43 B.C., and it was said that this comet was, in fact, the recently departed Julius Caesar, placed in the sky by the Gods. To me, this is evocative enough of Eärendil that I feel reasonably sure Tolkien drew on this legend for his own. Drew on it secondarily, I should add, as he was certainly thinking primarily of the Germanic myth of Aurvandil’s Toe.  At the same time, this specific use of flammifer by Ovid suggests the connection might be more than trivial. Am I onto something, do you think?
And actually, there’s another tantalizing thread one can follow. Centuries later, Alexander Pope echoed Ovid’s lines when he wrote: “A sudden Star, it shot thro’ liquid air, / And drew behind a radiant trail of hair.” Anyone know the source? Bueller? Bueller? It’s “The Rape of the Lock”, which suggests, albeit faintly, the “rape of the Silmarils” in The Silmarillion, passim. Lest this sound too far-fetched, I should point out that connections between Tolkien and Pope have been suggested before. 
Returning to the Italian, fiammifero is, today, an extremely common word, meaning a “match(stick)”. Even though its direct linguistic equivalent, such a familiar, colloquial word would hardly do for the Italian rendition of Tolkien’s Flammifer, would it? Actually, in the days before matches, fiammifero had the same meaning as its Latin forebear, as one finds it used in Boccaccio’s Decameron, e.g., fiammifere folgori di Giove “the fiery thunderbolts of Jove” — but even so, the word, today, would not be suitable at all. By the turn of the 20th century, the original meaning was already being marked in Italian dictionaries as lingua fuori d’uso “language outside use” . So what is an Italian translator to do?
Tolkien had a recommendation of his own. In a letter to his publisher, he tartly complained:
In principle I object as strongly as is possible to the ‘translation’ of the nomenclature at all (even by a competent person). I wonder why a translator should think himself called on or entitled to do any such thing. That this is an ‘imaginary’ world does not give him any right to remodel it according to his fancy, even if he could in a few months create a new coherent structure which it took me years to work out. 
The quotation is reproduced in Tolkien’s Nomenclature, a guide meant to assist translators (as well as to convey Tolkien’s extreme displeasure at some of the efforts to date). Tolkien mentions Westernesse in the Nomenclature, but not Flammifer. But a translator who took Tolkien’s words to heart (if aware of them) would leave the word untouched. That is, in fact, just what the Italian translator has done, rendering the final line of Bilbo’s “Canto di Eärendil,” “Il Flammifer dell’Ovesturia” .
This is a good solution, but I find it interesting because of the relative paucity of fl in Italian. In fact, the poem also exhibits the retention of words like Nimbrethil — again, in accordance with Tolkien’s sage advice — but which is interesting because the th sounds in thin/then do not exist in proper Italian phonology. In the Italian translation of Appendix E, readers are advised, somewhat unhelpfully: “TH è il suono dolce del th inglese” (omitting Tolkien’s example of “thin cloth”), and “DH rappresenta il suono dolce del th inglese, come in these clothes” . Both are called a suono dolce, which I would have presumed to correspond in this case to a “voiceless sound”, as opposed to a suono duro — isn’t one of these wrong? And do native Italians without first-hand English experience know how to pronounce these words? Perhaps not!
 Gilliver, Peter, Jeremy Marshall, and E.S.C. Weiner. The Ring of Words: Tolkien and the Oxford English Dictionary. Oxford: Oxford University Press, 2006, pp. 132–3.
 For a thorough examination of the most likely sources for the Eärendil myth, see Hostetter, Carl F. “Over Middle-earth Sent Unto Men: On the Philological Origins of Earendel Myth,” Mythlore 65 (Spring, 1991): 5-8. Carl has not discussed Ovid in this essay, however, so I believe I may have the makings for a nice scholarly note. :)
 See for example, Tolley, Clive and Raimund Kern. “Tolkien’s ‘Essay on Man’: A Look at Mythopoeia.” Inklings: Jahrbuch für Literatur und Asthetik 10 (1992): 221-39.
 See for example Edgren, Hjalmar. An Italian and English Dictionary, with Pronunciation and Brief Etymologies. New York: Henry Holt, 1901, which so identifies fiammifero = “flammiferous; kindling; burning”, p. 176.
 Tolkien, J. R. R., Humphrey Carpenter, and Christopher Tolkien. The Letters of J.R.R. Tolkien. Boston: Houghton Mifflin, 1981, pp. 249–50.
 Tolkien, J.R.R. Il Signore degli anelli. Tradotto per Alliata di Villafranca V. Bompiani, 2000, p. 301.
 Ibid., pp. 1329, 1327.