(i ngîl = i ñîl, o n’gîl, construct gil) (bright spark, silver glint), no distinct pl. form except with article (in gîl = i ñgîl), coll. pl. giliath **(RGEO, MR:388). Poetic †êl (elen-, pl. **elin, coll. pl. elenath) (RGEO, Letters:281, WJ:363).
Sindarin
elenath
noun. starry host, all the host of the stars of heaven
o menel aglar elenath
from heaven on high the glory of the starry host
êl Archaic
noun. star
gîl
star
elui
adjective. starry
A neologism for “starry” coined by Gábor Lőrinczi from the VQP (VQP), an adjectival form of êl “star”.
A Sindarin word for “star” that is largely archaic and poetic, and is mainly used as element in names like Elrond (Let/281; WJ/363; Ety/EL); the more usual word for “star” in ordinary speech was gil (RGEO/65). However, the collective form elenath is still used in common speech to refer to the entire host of stars (WJ/363). The plural of êl is elin, as this word was derived from ancient ✶elen, and the final n that was lost in the singular was preserved in the plural. In some cases Tolkien posited a restored analogical singular elen from the plural form (PE17/24, 67, 139), but this isn’t in keeping with the notion that the word was archaic, so I would ignore this for purposes of Neo-Sindarin.
Conceptual Development: This word and its root first appeared in The Etymologies of the 1930s, where N. el “star” was derived from the root ᴹ√EL of similar meaning, but was “only [used] in names” (Ety/EL). It seems Tolkien introduced the root to give a new etymology for names like N. Elrond and N. Elwing, which initially appeared under the root ᴹ√ƷEL “sky” (Ety/ƷEL).