Nan means "valley" in Sindarin. Robert Foster translates the whole name as "Valley of star-dusk" (el + moth "stardusk").
Sindarin
nan elmoth
place name. *Valley of Starry Dusk
Elements
Word Gloss nan(d) “vale, valley, vale, valley, [ᴱN.] dale; [N.] wide grassland; [G.] field acre” êl “star” moth “dusk” Variations
- Elmoth ✧ WJI/Elmoth
Nan Elmoth
Nan Elmoth
The forest where Thingol and Melian met (S/55), a combination of nan(d) “valley”, êl “star” and moth “dusk” (SA/nan(d), moth).
Conceptual Development: In “The Lay of Leithian Recommenced” from the 1950s, Tolkien considered some variant names for this forest: S. Glad-uial >> Glath-uail >> Gilammoth (LB/349). The first of these also appeared on the Silmarillion map from the 1950s (WJ/183, 188 note #48).