The capital of Arnor (LotR/244). Christopher Tolkien translated it as “Tower of the West” (SI/Annúminas), a combination of annûn “west” and minas “tower” (SA/andúnë, minas).
Conceptual Development: When this city first appeared in Lord of the Rings drafts from the 1940s, it was named N. Torfirion “Westermanton” (TI/144). In an early version of the Tale of Years the city was called N. Dunhirion (PM/167). Both of these variants were eventually replaced by Annúminas.
annûn (“west, sunset”) + minas (“tower”) #The assimilation of nm > mm > m could be “internal nasal mutation”.