The Maiden of the Sun who guided the solar orb through the heavens after it was created (S/99). Her name is likely a compound of árë “sunlight” and the feminine suffix -ien.
Conceptual Development: When she first appeared, this character’s name was ᴱQ. Urwen(di) “Sun-maiden” (LT1/179, LT1A/Urwen), combining the early name of the Sun, ᴱQ. Ûr, with ᴱQ. wen(di) “maiden”. Her name was later revised to ᴹQ. Úrien (SM/97, SM/170) >> ᴹQ. Árien (SM/99, 168) >> ᴹQ. Arien (LR/243, Ety/AR¹).
In later writings, the name sometimes appeared with the long Á (PE17/148, MR/376) but usually had a short A, and this is the form appearing in the later drafts and published versions of The Silmarillion (MR/136, 198; S/99). In his late notes on the cosmology of Middle-earth, Tolkien consider numerous variant forms for this name: Áren, Ār(i), Ārië, Āzië and even a (rejected) masculine form Auron (MR/376, 380), but none of these variants appeared in the narratives. The early form Úrien also briefly reappeared in some linguistic note from the 1950s (PE21/86).
An earlier name for Q. Arien (SM/97, LR/243). Its initial element seems to be Ûr, an early name Tolkien used for “Sun”.