A word for “sunlight” and “warmth (especially of the sun)” as well as the older name of tengwa #31 (k), which was originally used for the sound [z] matching the archaic pronunciation of this name: †áze (LotR/1123). When this sound fell out of use in Quenya (becoming r) the tengwa was repurposed for [ss] and given a new name: Q. essë. The word árë was derived from the root √AS “warmth” (PE17/18, 148; VT43/18).
Conceptual Development: In The Etymologies of the 1930s, ᴹQ. are has the sense “day” as a derivative of the root ᴹ√AR of the same meaning (Ety/AR¹), and it appears with this gloss in some later writings as well (PE17/148, PM/127). By the time Tolkien was writing The Lord of the Rings appendices, though, he had changed the sense of this word to “sunlight” as described above. The sense “day” was transferred to the words aurë and ré.
árë noun "day" (PM:127) or "sunlight" (SA:arien). Stem ári- _(PE17:126, where the word is further defined as "warmth, especially of the sun, sunlight"). Also name of tengwa #31; cf. also ar # 2. Originally pronounced ázë; when /z/ merged with /r/, the letter became superfluous and was given the new value ss, hence it was re-named essë (Appendix E)_. Also árë nuquerna *"árë reversed", name of tengwa #32, similar to normal árë but turned upside down (Appendix E). See also ilyázëa, ilyárëa under ilya. In the Etymologies, this word has a short initial vowel: arë pl. ari (AR1)