Luvailin appears only in the Unfinished index. The name Shadowmere is said to be its "translation". Though Tolkien did not provide an explanation of the latter, fans have speculated that Luvailin seems to contain the elements luv- *"shadow-" (seemingly from √LUM, LUB "shadow, darkness",) and ailin "pool, lake",[note 1] and that it is unclear if the name is supposed to be Quenya or Sindarin.
Other versions of the legendarium
In an early version of Galadriel's Song of Eldamar, appears the lines:
And by the strand of Tirion there grew a golden Tree.
Beneath the stars of Ever eve in Eldamar it shone,
In Eldamar beside the walls of Elven Tirion.
But far away and far away beyond the Shadow-meres
- J.R.R. Tolkien, "Unfinished index for The Lord of the Rings", in Wayne G. Hammond and Christina Scull (eds), The Lord of the Rings: A Reader's Companion, p. 217
- J.R.R. Tolkien, The Lord of the Rings, The Fellowship of the Ring, "Many Meetings"
- Mark Fisher, "Shadowmere" dated 8 November 2008, Encyclopedia of Arda (accessed 22 November 2013)
- J.R.R. Tolkien, "Words, Phrases and Passages in Various Tongues in The Lord of the Rings: Eldarin Roots and Stems", in Parma Eldalamberon XVII (edited by Christopher Gilson), pp. 161, 168
- J.R.R. Tolkien, Christopher Tolkien (ed.), The Lost Road and Other Writings, Part Three: "The Etymologies" s.v. AY-, p. 349
- "Shadowmere, a "translation" of Luvailin", The Lord of the Rings Fanatics Plaza: Forum (accessed 18 November 2013)
- J.R.R. Tolkien, Christopher Tolkien (ed.), The Treason of Isengard, "XIV. Farewell to Lórien", pp. 284, 292 (note 35)