[Iolossë] place-name "Everlasting Snow" = Taniquetil (GEY, EY; changed to Oiolossë)
Quenya
oiolossë
place name. Ever (Snow) White
Iolossë
everlasting snow
oiolossë
Oiolossë
Oiolossë (also spelled Oiolosse) is Quenya and means "Ever-snow-white", "Everwhite/snowy", or "Everlasting snow". The name seems to consist of oio "ever" (cf. root OY-) and losse "snow". In Eriol's Old English translations, Oiolossë is referred to as Sinsnaw, Sinsnaewen "Ever-snow". The Sindarin equivalent of Oiolossë was Amon Uilos.
-o
of goodness
-o (1) genitive ending, as in Altariello, Oromëo, Elenna-nórëo, Rithil-Anamo, Rúmilo, Lestanórëo, neldëo, omentielvo, sindiëo, Valinórëo, veryanwesto, q.v. In words ending in -a, the genitive ending replaces this final vowel, hence atto, Ráno, Vardo, vorondo as the genitive forms of atta, Rána, Varda, voronda (q.v.) Following a noun in -ië, the ending can have the longer form -no, e.g. *máriéno "of goodness" (PE17:59, but contrast sindiëo "of greyness" in PE17:72). Where the word ends in -o already, the genitive is not distinct in form, e.g. ciryamo (q.v.) = "mariner" or "mariners". Pl. -ion and -ron, q.v.; dual -to (but possibly -uo in the case of nouns that have nominative dual forms in -u rather than -t). The Quenya genitive describes source, origin or former ownership rather than current ownership (which is rather covered by the possessive-adjectival case in -va). The ending -o may also take on an ablativic sense, "from", as in Oiolossëo "from (Mount) Oiolossë" (Nam), sio "hence" (VT49:18). In some of Tolkiens earlier material, the genitive ending was -n rather than -o, cf. such a revision as Yénië Valinóren "Annals of Valinor" becoming Yénië Valinórëo (MR:200).
Taniquetil
high white horn
Taniquetil (Taniquetild-), place-name: the highest of the mountains of Valinor, upon which were the mansions of Manwë and Varda. Properly, this name refers to the topmost peak only, the whole mountain being called Oiolossë (SA:til). The Etymologies has Taniquetil, Taniquetildë ("q") (Ta-niqe-til) ("g.sg." Taniquetilden, in LotR-style Quenya this is the dative singular) "High White Horn" (NIK-W, TIL, TA/TA3, OY). Variant Taníquetil with a long í, translated "high-snow-peak"(PE17:26, 168).
oio
endless period
oio noun "an endless period" (CO) or adv. "ever" (SA:los). Oiolairë "Ever-summer" (name of a tree, UT:167; also in the name Coron Oiolairë, "Mound of Ever-summer". Oiolossë "Everwhite, Ever-snowwhite", a name of Taniquetil (OY), hence the translation "Mount Everwhite" in Tolkien's rendering of Namárië. See also SA:los. Explicit "mount" in Oron Oiolossë "Mount Everwhite" (WJ:403). Ablativic genitive Oiolossëo "from Mount Everwhite" in Namárië (Nam, RGEO:67, OY)
Another name for Taniquetil (LotR/377, S/37) variously translated as “Everlasting Whiteness”, “Ever-snow”, “Ever-white” or “Ever-snow-white”. This name is a compound of oi(o) “ever” and lossë “snow, snow-white” (RGEO/61).
Conceptual Development: In Silmarillion drafts from the 1930s, this name first appeared as ᴹQ. Ialasse “Everlasting Whiteness” (SM/81). A similar form ᴹQ. Iolosse appeared in The Etymologies (Ety/EY, GEY) and possibly also in the Silmarillion texts (LR/210), but it was rejected and replaced by its final form ᴹQ. Oiolosse (Ety/OY, LR/209).