Quenya form of the name of Ungoliant (WJ/14), a compound of [ᴹQ.] ungo “cloud, dark shadow” and [ᴹQ.] liante “spider” (Ety/UÑG, SLIG). Christopher Tolkien confessed that the Quenya form Ungoliantë was used in Silmarillion drafts from the 1930s forward, but he changed it to Ungoliant in the published version of The Silmarillion for compatibility with The Lord of the Rings (LR/299).
Conceptual Development: In the earliest Lost Tales her name was ᴱQ. Ungwe Lianti or Ungweliante, translated “great spider who enmeshes” (LT1/152). At this stage, this name was likely a combination of ᴱQ. ungwe “spider” and a derivative of the root ᴱ√LIYA, perhaps ᴱQ. liante “tendril” (LT1A/Ungwë Lianti). Her Gnomish name G. Gwerlum “Gloomweaver” (ᴱQ. Wirilóme) was of a different origin (LT1A/Gwerlum).
The name ᴹQ. Ungweliante appeared in The Etymologies from the 1930s (Ety/UÑG), but at this stage Tolkien reversed the meaning of its elements, with its initial element ᴹQ. ungwe “gloom” and the final element ᴹQ. liante “spider” (Ety/UÑG). Furthermore, in the contemporaneous narratives the earlier name was replaced by ᴹQ. Ungoliante, which appeared in The Etymologies beside Ungweliante, but with an initial element of ᴹQ. ungo “cloud, dark shadow” (Ety/UÑG, SLIG).
Tolkien used Ungoliantë for her Quenya name in all later writings, but he did not revisit its etymology. In Silmarillion drafts from the 1930s, Ungoliantë was glossed “Gloomweaver” (LR/230), but Tolkien did not translate the name in later works. The later words Q. ungwë “spider’s web” (LotR/1122) and S. ungol “spider” (Let/180) indicates that Tolkien reversed himself again and decided that the initial element Ungo- meant “spider”: the root √ungu- for “spider words” appears in later writings (PE22/160). This entry uses “Gloomweaver” as the best available translation, but it is most likely a holdover from earlier G. Gwerlum. Using the derivation from The Etymologies, a more literal translation would be “✱Shadow Spider”, but even that is questionable given Tolkien’s later rearrangement of the roots.
Ungoliantë fem. name "Ungoliant" (the Spider, ally of Morgoth); also Ungweliantë (UÑG, DYEL, SLIG)