Great points all... and to answer such requires a far more in-depth discussion into matters both historic, for that area, and linguistic.
First off, any Christian priest involved in transcription and... more to the point... translation would have to have had an extensive knowledge of Greek given that the Christian New Testament was almost exclusively written first (as far as we have been able to discover) in Greek. Thus to translate any of them into other languages, or by extension, from those languages into yet other languages, would have made it very important that the original Greek texts be available and very clearly understood so as to help ensure textual as well as contextual accuracy.
However, as relates to the Greek "pij" and Slavic "pir" verbs, whose meanings are quite different though related, this topic has already been investigated at length by other far more educated persons than those herein opining. In particular, a Ph.D in the field of Slavic languages and as relates directly to the issue of the etymological origins of our modern term "vampire", recently published by far the best treatise on this topic.
In his wonderful book "Slayers and their Vampires," Dr. Bruce McClelland provides a wonderful and in-depth treatise of the origins of our word "vampire" drawing not only from his expertise but also that of other more pre-emminent vampirologists including, perhaps most notably, Dr. Jan Perkowski (author of "Vampires of the Slavs" and "The Darkling).
However before I venture into this, it is first critical that we first dispel a misconception raised regarding name origins that has particular importance to the issue at hand. As we are about to see, while centuries later the word "Upir'" may have become a common name, yet initially it was not a name at all, but instead a term that identified what its appellant did. While on the face of it this might seem strange, yet this is common worldwide.
In English, for example, names like "Taylor," "Smith," "Shoemaker," "Farmer," "Mason," etc., were not originally actual names at all... but instead helped to more correctly identify the possessors thereof in accordance with their trades. Only later did these become common names, as well. So also, the history of other names can be found that identified those ascribed with such names as members not of a particular occupation, but as part of a particular group, be it religious, fraternal, or otherwise.
This is how many names came into being: first, as a moniker to identify a person with his trade, or a group to which he belonged; then later, usually much later, developing into common names.
Okay, with that said, let's read a portion of Dr. McClelland's doctoral thesis, also largely reproduced in an appendix of his recent book "Slayers and their Vampires", as can be found online HERE (for purposes of both brevity and conciseness, I am providing hereafter only certain key excerpts therefrom as relates to this discussion):
"The earliest written reference to the term vampir is also Old Russian, appearing in the margin of a (partially?) Glagolitic text dated to 1047, a reproduction of which was made in 1499. The actual form of the inscription is popú upirü liõy, upir' being the East Slavic variant of South Slavic vampir..."
"...Upirü, then, in all likelihood must have designated a category of human, a member of a group whose attributes we are about to examine. Perkowski is of the opinion that the word vampir consists of two Slavic roots, or at least two morphemes. Furthermore, it is likely that the second term, pir, is the same word that we have encountered elsewhere in our discussion, pertaining to 'feasting' or 'libation.' The Old Slavonic meaning is particularly associated with wedding feasts... "
(NOTE: the Slavic "wedding feasts" of the day contained a strong and Pagan sexually orgiastic element... and additionally, to a Christian of those early times, the term "feast" possessed a far more resonating origin: that of the "Agape" (love feasts) whose very sexual nature was attested to by both Roman historians as well as found strongly alluded to in the Book of Jude as well as in II Peter, Chapter 2, in the New Testament.)
"... The second possibility, vú pirú, is a prepositional phrase, and requires the assumption of some sort of epenthetic nasal [m] between the back reduced vowel [â] [76] and the initial [p] in Bulgarian: vâ pir > vâm pir [77] This compound would mean, presumably 'in (or: into) the feast', vú being a preposition that may be glossed as 'in, into; among'. In this case, a 'vâ-pir', designating a member of a group, might refer to someone who participated in feasting (It is harder to justify the notion that pirú was ever some sort of nomen agentis, such that vâ pir would mean 'he who drinks in', an etymology proposed by Rudnyækyj.)..."
Additionally, and to be fair here, McClelland also here provides his view as to the meaning of the adjective "likhyj", as well. His view, as found in this same thesis, is that this term was a self-denegrating one meaning, essentially, "evil." Though he also admits that we do not know the actual meaning given that the word itself has not been used in several centuries and, like the word "vampire" itself, must have originated meaning something very different from what we might imagine today.
However, as Artemka argued correctly earlier, and as I also pointed out to Dr. McClelland, no Christian priest no matter how humble or self-denegrating in character would ever call himself... "evil." To do so would be to jeopardize not only his position and his priesthood by so demonizing himself, but might in fact subject him to excommunication and perhaps even death as a heretic for so confessing himself to be.
The fact is that just as Dr. McClelland's opinioin that the word "likhyj" meant "evil" is just as much a guess as is Artemka's view that it means "swift." Both translations are based upon the best-guess estimates using words in modern Russian that are the most homophonic with "likhyj." Again... I go back to my original argument that the only way we can arrive at any probable definition is to see how this particular adjective was used contemporary with its 1047 CE usage. And as I have stated, the only synonym that works perfectly and in context is a word synonymous with: intractable, never-ending, permanent, long-lasting, unstoppable, and/or incurable, even.
*Whew!* Aren't ya all glad that's done?!
;)
