A sobriquet of Morwen translated “Elfsheen” (S/155) or “Elven-fair” (Let/281). Its initial element is †Eledh, an archaic Sindarin word for “Elf”, which in ordinary speech was Edhel (SA/êl, Let/281). The meaning of the second element is less clear. Given the translation, it might be a lenited variant of gwân “fair” (PE17/165) or of the root √GWEN (PE17/191), but could also be the suffixal form -wen of gwend “maiden” common in female names (Ety/WEN).
Conceptual Development: In Silmarillion drafts from the 1930s, this name appeared originally as N. Eledwen (SM/319), later revised to N. Eledhwen (LR/147). At this stage, N. Eledh was the ordinary Noldorin word for Elf, and was specifically given as an element of the name Eledhwen in The Etymologies (Ety/ELED). In these Silmarillion drafts, this name was already translated as “Elfsheen” (SM/319, LR/276), and in The Etymologies her name was initially translated “Elf-fair”, but this gloss was rejected and replaced by “Elf-maid” (Ety/ELED).
In Tolkien’s writing, the root √WEN(ED) (from which S. gwend “maiden” is derived) was usually associated with youth and virginity, but sometimes also with beauty, as for example in the rejected root √GWEN “fair, beautiful” (PE17/191). This vacillation may be reflected in the different translations of the name Eledhwen.
In Silmarillion revisions from the 1950s-60s, Tolkien changed this name to S. Edhelwen to be consistent with the later Sindarin name for “Elf” (WJ/142, WJ/273), but Eledhwen also appeared in his later writings (e.g. Let/281 from 1958) and this is the form that appeared in the published version of The Silmarillion.
eledh (“elf”) + gwend (“woman, maiden”, [Etym. ELED-]) [Etym. WEN-]: since it shows no -d even in the archaic spelling, it probably contains derivative of WEN-, not WENED- stem and the last element is Ilk. gwen “girl”; in Grey Annals the translation is given “Elfsheen”.