Earlier of Elurín (LR/147 note #42). This name also appeared in The Etymologies, where it seems to be a combination of el “star” and the lenited form of rhûn “east” (Ety/RŌ).
Noldorin
el
noun. star
ell
noun. sky
elrûn
masculine name. *East-star
elbereth
feminine name. Queen of Stars, (lit.) Star Queen
elf
noun. friend
linglor(el)
feminine name. Linglor(el)
Earliest names for S. Nimrodel in Lord of the Rings drafts from the 1940s, also appearing as Inglorel and (rejected) Taiglin. The meaning of these names is unclear, but like her later name, they were also applied to the river named after her.
mellon
noun. friend
meldir
noun. friend
meldis
noun. friend
mellon
noun. friend
geil
noun. star
thond
noun. friend
geil
noun. star, bright spark
giliath
noun. all the host of stars
min
fraction. one (first of a series)
min
cardinal. one
An element meaning “sky” in several names from The Etymologies of the 1930s: N. Elfaron “Sky-hunter” (Ety/SPAR) and N. Elthoron “Eagle of the Sky” (Ety/THOR). It was derived from the root ᴹ√ƷEL “sky” which had an Old Noldorin form: ON. elle (Ety/ƷEL). However, Tolkien said “In Noldorin and Telerin this is confused with EL star”, implying that the word was not used in modern language; an earlier but rejected version of this entry had archaic N. †ell, el “sky” (EtyAC/ƷEL).
Neo-Sindarin: Despite the above statements, ell is probably the best attested option for “sky” in Neo-Sindarin, and I would use it as such, since it is in fact distinct from S. êl “star”, a word that is itself archaic/poetic versus more common S. gil.