Elfinesse

The name Elfinesse belongs to an early phase of Tolkien's writing, before he had considered the wider world of Middle-earth in the Ages beyond the First. Elfinesse in this original sense belonged to the realms of the Elves in Beleriand, but it might reasonably be extrapolated to incorporate lands such as Lindon or Lórien in later times. (Indeed Lórien is described as belonging to 'Elvendom', a word that unmistakably recalls the earlier Elfinesse.)

The -ness ending has two valid pronunciations, and in early Middle English would be have been pronounced as something like 'nesseh', with the final e sound individually pronounced. This final e sound was later lost (so -ness would pronounced simply as 'ness'). We can be sure that Tolkien intended this later, simplified pronunciation from examples in his poetry (for example, he rhymes 'Elfinesse' with 'tenderness' and 'sorrowless').

The ending -nesse appears in the name Westernesse in the chivalric romance of King Horn, which possibly refers to a land on a western promontory (from Old English naess), but may be taken more broadly as 'western land' or 'western realm'. Tolkien preferred the broader interpretation of 'land' or 'realm', and applied the same name to the island kingdom of Westernesse or Númenor in the Great Sea. In this broader sense of -nesse, the ending is used in Elfinesse (also given as Elvenesse) for the lands of the Elves.

The name 'Elvenhome' is almost always used for Eldamar in the West (and indeed 'Elvenhome' is a direct translation of Elvish Eldamar). We do, however, have a single exception, in Aragorn's song of Tinúviel beneath Weathertop, where 'Elvenhome' is used of a land of the Elves eastward of the Great Sea, and in that particular sense its usage is comparable with the name Elfinesse.