Etruscan "esi"... What is it?

I'm still going through my own personal linguistic database, updating things and refining translations. I now have 790 words with references to their inscriptions, what other experts have claimed each word means (really handy to keep your head above water in a field that is just swimming in b.s. and self-contradictions), and even external connections to other Etruscan-related languages like Lemnian, Rhaetic, Eteo-Cypriot and Minoan. (Yes, dagnammit! I blurted it out. Minoan is related to Etruscan. Surprise! If it's not, I will eat my own spleen.) As I find more connections, my database just keeps on growing and I've been thinking of converting some of my collected info into a kind of pdf draft for people to check out just to prove I'm not lying about making my own database.

Sometimes as I'm going through things, cross-checking translations between inscriptions, some words pop out at me and their mystery drives me nuts. With more obscure words, Pallottino, Bonfante, DeGrummond, Rix, etc are all unhelpful because even experts are as clueless as the common hobbyist. So I spend much thought into trying to crack these words so that I can finally move on with my life and clean the livingroom. That's what happened to me with this pesky Etruscan word:

• eśi [LL 3.xxi, 8.v, 8.xxxii, 10.xi, 10.xxxii, 11.xxxi], eśi-c [LL 10.xxi] (na.sg.)
  (LL = Liber Linteus)

Only found uninflected. No clues there. Really irritating. What a snag. We find it in the following environments in Etruscan:

• Vinum eśi sese, ramue, racuśe, faśei-c. [LL 8.xxxii-xxxiii]
• Etnam ic, esvi-tle eśi. [LL 8.v]
• Χimθ, anan-c eśi vacl ścanin. [LL 10.xi-xii]
• Lei-tr-um zuθeva zal, eśi-c ci, halχza θu, eśi-c zal mula. [LL 10.xx-xxi]

But this isn't very helpful because many of the above words surrounding eśi are also a mystery. We can recognize some words like vinum "wine", vacl "votive", θu "one", zal "two", and ci "three". It appears that the phrase in the last sentence, eśi-c ci, proves that it is a countable noun (ci = "three" and -c = "and"; thus "and three X"). This is somewhat helpful because we know that it's not a liquid or some kind of material. It is the object of the verb mula which I believe is a presentive verb meaning "blesses", so it appears we're dealing with something pointing to a kind of gift to the gods.

Yet, in the other instances, we find the word postposed to other nouns such as vinum and esvi, the latter term probably being another kind of sacred offering. In those cases, it looks more like an adjective than a noun.

So what is it? An adjective? A noun? Both? In Etruscan, the line between noun and adjective isn't very pronounced so asking whether it's a noun or an adjective is a pointless exercise. It can be both. I think of vacil "votive", for example, which also acts just as nebulously by being found as a noun on its own or postposed to other nouns like an adjective. As an adjective, it means "as a votive" but there is no difference in marking to overtly signal that it's an adjective (eg. vinum vacil = "the votive wine" or "the wine as a votive") . Only context can help us deduce the word category at any given moment.

But so far none of these grammatical factoids are helping me crack what eśi really is. Time will tell, I suppose.