A late remnant of earlier names for the Sun: ᴱQ. Ûr and ᴹQ. Úrin. In Silmarillion revisions from the 1950s-60s, this name was changed from Úrin >> Naira >> Vása (MR/198), but the form Úr(in) occasionally appeared in some later writings (PE17/148, MR/377). This name was a derivative of the root √UR “heat, be hot” (PE17/148).
Conceptual Development: In the earliest Lost Tales, this name was ᴱQ. Ûr, Ur or Úri “Sun”, but literally meaning “Fire” (LT1/187, QL/98). The name became ᴹQ. Úrin in Silmarillion drafts from the 1930s (LR/240). It was rejected in The Etymologies along with the root form ᴹ√UR, but reappeared sometimes in later writing as noted above.
The most common Quenya name for the Sun derived from primitive ✶Anār, an augmented form of the root √NAR “fire” (Let/425; PE17/38; Ety/ANÁR; SD/302, 306).
Conceptual Development: This term appeared in Silmarillion drafts of the 1930s with the gloss “Heart of Flame” (LR/240) and as ᴹQ. Anar “sun” in The Etymologies of the 1930s, already with the derivation given above (Ety/ANÁR, NAR¹).