nelya adj. "third" (VT42:25; also neldëa). Pl. Nelyar "Thirds", the original name of the Teleri (or rather the direct Quenya descendant of the original Primitive Quendian name) (WJ:380).
Quenya
nelya-
verb. to thicken, congeal
nelya
third
nelya Archaic
ordinal. third
nelya-
verb. to thicken, congeal
neldë
cardinal. three
neldë cardinal "three" (SA:neldor, NÉL-ED, VT47:11, VT48:6). Eleni neldë "three stars", archaic elenion neldë = *"of stars three". Genitive "of 3 stars" = elenion neldë (for archaic elenion neldëo) (VT49:45; see 54 regarding neldion as the gen. pl.) Cf. also nelya, neldëa, Neldië.
neldë
cardinal. three, three; [ᴱQ.] four
The Quenya word for “three” derived from √NEL(ED) of the same meaning (VT47/10-11; Ety/NEL).
Conceptual Development: This use of nelde for “three” dates back all the way to Early Qenya Grammar (EQG) of the 1920s (PE14/49, 82). However, in the Qenya Lexicon of the 1910s ᴱQ. nelde was “four”, appearing under the early root ᴱ√NELE “point” and serving as the basis for the word ᴱQ. neldenelqa “square” (QL/65). In this 1910s document, ᴱQ. ole was “three” derived from the early root ᴱ√OLO “tip” (QL/69).
neldëa
third
neldëa ordinal "third" (VT42:25); also nelya. Cf. neldë.
neldëa
ordinal. third
olë
cardinal. three
olë (2) cardinal "three" (LT1:258; in LotR-style Quenya Tolkien replaced this "Qenya" form with neldë)
There was a set of possible verb forms lelya, nelya, delta, delya (the last two probably primitive forms) appearing in a note probably from the mid-1960s, with a difficult-to-read gloss that seems to be something like “thick, thicken & congeal” according to Christopher Gilson (PE17/17). This note included the root √DEL “thick, dense”; the form nelya hints at a possible root change to √NDEL, or it could some sort of assimilation/disimilation of ancient d to n rather than the usual change of initial d to l. All these verb forms were rejected along with the root √DEL.
Neo-Quenya: Since we have no other words of similar meaning in Tolkien’s later writings, I would salvage ᴺQ. nelya- “to thicken, congeal” for purposes of Neo-Quenya, and assume it is derived from a Neo-Root ᴺ√NDEL “thick, dense”.