The Quenya word for the special Elvish drink of Rivendell, more commonly known by its (Sindarin) name S. miruvor (LotR/290), itself a loan word from Quenya (PE17/37). The Quenya word dates all the way back to the earliest versions of the Legendarium, with ᴱQ. miruvōre “nectar, drink of the Valar, sweet drink” appearing in the Qenya Lexicon of the 1910s (QL/61), and the shorter form miruvor appearing The Lost Tales from this same period (LT1/153).
Possible Etymology: In notes from 1967, Tolkien admitted this word was inspired by Germanic među + wōþi = “sweet mead”, which would have become miřuwoři in the English language branch (PE17/64). In the Qenya Lexicon of the 1910s it was a combination of ᴱQ. miru “wine” and ᴱQ. wóre “sweet” (QL/61, 104). In notes from the late 1950s, Tolkien redefined it as a combination of √MIR “precious” and ✶wōri “juice”, but then declared this was a false etymology (PE17/37-38). Indeed, in the Quendi and Eldar essay of 1959-60 Tolkien said the Quenya word was based on Valarin mirubhōze (WJ/399), elsewhere glossed “a honey wine” (PE17/38), with the element Val. mirub being “wine”.
miruvor, full form miruvórë noun "mead", "a special wine or cordial"; possessive miruvóreva "of mead" (Nam, RGEO:66; WJ:399).In the "Qenya Lexicon", miruvórë was defined "nectar, drink of the Valar" (LT1:261).