The most common Quenya word for “star”, mentioned very frequently, derived from an extended form ✶elen of the root √EL “behold” (PE17/67; WJ/360, 362). Its usual plural form is eleni, but it has an archaic plural †eldi sometimes used in verse, the result of the Ancient Quenya sound whereby [[aq|[ln] became [ld]]] after the ancient plural underwent the Quenya syncope, ✶elenī > AQ. elni; its normal modern plural form eleni was actually a reformation from the singular (PE17/57, 151; WJ/362).
Conceptual Development: This word first appeared in The Etymologies of the 1930s, though in the original entry for the root ᴹ√EL Tolkien said it was poetical and gave variants ellen and elena (Ety/EL).
elen noun "star" (SA:êl, elen, EL, VT49:39); pl. eleni (occasionally in verse: eldi) (WJ:362, PE17:127); partitive pl. elelli for elenli (PE17:127), gen. pl. elenion in the phrase Elenion Ancalima "brightest of stars" (LotR2:IV ch. 9; see Letters:385 for translation); elen atta "two stars" (VT49:44), genitive elen atto "of two stars" (VT49:45), eleni neldë "three stars", archaic elenion neldë = "of stars three". Genitive "of 3 stars" = elenion neldë (for archaic elenion neldëo) (VT49:45). Allative elenna "starwards" used as name of Númenor _(Silm; see Elenna)_; ablative pl. elenillor "from stars" in Markirya. **Nai elen siluva ***"may a star shine", VT49:38.