The general public, if they ever should come across the topic of the Etruscans at all, doesn't fully understand the fact that most foremost Etruscologists lack linguistic training and have published many falsehoods about the translation of Etruscan words and grammar. Academics with degrees are hardly infallible and are not experts in everything they touch so it is our duty as readers to question what we read. Sometimes even a student can show a sensei a thing or two.
Etruscan usil is unanimously translated as "sun". We see this published everywhere, so I realize that questioning it only arms dismissive spindoctors to label me an iconoclast who thrives on sacrilege. I can do little about petty politics and time is better spent constructively getting at the heart of this nonsense by asking a direct question and seeking an answer to it.
What proofs demonstrate clearly that usil must mean "sun"?
The answer to that is straight-forward. We see a couple of mirrors where the word "usil" is inscribed next to a character shown in a kind of "aura" (see pic: ). Further, Massimo Pallottino in The Etruscans (1975) had connected usil to a Sabine word ausel- and this etymology seemed to lull critics into submission. What here is there to question?
Well, this isn't the whole story at all. To translate a word properly we should seek consistency by taking note of all instances of this word, including any inflected forms that we can identify with our grammatical model of Etruscan. This is called the combinatory method and it is a fully accepted part of the mainstream linguist's toolkit. Linguists also are taught to avoid the trap of folk etymology and avoid building one's case on deceptive look-alike words. Thus the Sabine doppelganger, without any other evidence to back it up, has no weight particularly when the lack of initial a- in ausel- in the Etruscan counterpart cannot be explained without special pleading (nb. Etruscan allows au/v- at the beginning of words: avil, Aule, avratum, etc.). These loose threads just aren't convincing in linguistics.
I've been building up a personal computer database of Etruscan vocabulary and any instances in indexed artifacts to keep ultra-organized. Currently I have the following specs on this etymon:
usil [LL 7.xi; TLE 417] (na.sg.) // usils [TLE 719] (gen.sg.) // usli [LL 7.xiii] (loc.sg.)
(LL = Liber Linteus, TLE = Testimonia Linguae Etruscae)
So since we are trying to expose the inner contradictions of Massimo Pallottino's translation, we should start by accepting Massimo Pallottino's own grammatical sketch of Etruscan that explains that -s is a genitive marker (conveying the word "of") and -i is a locative marker (equivalent to English prepositions of location: "at", "on", "upon", "in", etc.). Already, we can see a problem of consistency.
If usli of the Liber Linteus is the locative case form of the unmarked nomino-accusative case form usil as attested on the mirrors, translating it as "at/in/upon/on the sun" is utterly inane. Before we seek excuses, let me remind you that no one has the logical justification to "tweak" any translation that doesn't fit with more ad hoc assumptions. That conduct is not helpful.
It gets worse. We find usils on the back of the Piacenza Liver (see http://users.tpg.com.au/etr/etrusk/po/liver.html) and it could only be understood as a genitive form. It is found not alone, but together with the word tivr which is well attested to mean "month" in the Liber Linteus as well as in a few funerary inscriptions (TLE 181, TLE 749). It may be also translated as "moon" since this is normally a synonym for "month" in countless languages including English. Yet if these facts are all kosher, this gives us "month/moon of the sun". Now, what month is that on the as-yet-obscure Etruscan calendar pray tell? On second thought, do not pray tell. We can't throw logic out the window and drum up any old excuse about why "month of the sun" is somehow supposed to make sense, because it clearly doesn't.
There is a notable derivative of usil, namely *uslan, which is attested in its locative, uslane (LL 5.xxi). We must recognize its context, found in a sentence "Cis-um thesane uslane-c mlache." We know that the word thesan means "dawn" since a goddess by that name is attested on mirrors too but her mythological connections are less controversial. So if thesane means "at dawn", it specifies a time of action. Since -c is the conjunctive, usilane too is part of this temporal noun phrase. Thus, it must refer to a point in time on a par with "at dawn". Symmetry seems the simplest answer, leading us to a more sensible translation of usilane as "at dusk". The phrase probably reads "And the three [things] were blessed at dawn and at dusk." Does this fit all the other instances too?
If we translate usil as "dusk" or "setting" instead of "sun", we start to realize how the aura of the deity found on the mirrors may in fact represent the aura of the sun setting beneath the horizon. Furthermore, we again have a more satisfying symmetry on one mirror of deified Thesan "Dawn" and Usil "Dusk" before the god of the ocean. The symbolism is clear: Dawn and Dusk represent the two extremes of the horizon and it is the ocean that keeps the two apart. Further, the classical dawn-to-dusk metaphor as symbolic of an individual's lifetime from birth to death, as used in the famous Riddle of the Sphinx, is particularly meaningful on tomb offerings which these mirrors happen to be.
What then does the backside of the Piacenza Liver signify? Instead of "month/moon of the sun", we discover a more natural translation: "Moon of dusk" (or possibly "Setting Moon" if the "setting" in this context is intended to be of the moon rather than of the sun). What this moment signifies in Etruscan ritual would be a matter of debate but it at least shows a real point in time that finally works with the known morphology. That's leaps better than suggesting a month whose existence we have to hypothesize or an entirely nonsensical phrase "moon of the sun", all based on whimsical interpretations of artifacts, ad hoc folk etymologies, and a basic lack of respect for linguistic principles.