Sindarin name of the “White Mountains” (LotR/258), more literally “White-horns Mountains” (UTI/Ered Nimrais). This name is a combination of the plural of orod “mountain” and the plural of Nimras “White Horn” (SA/nim, ras; PE17/89, 168).
Conceptual Development: In Lord of the Rings drafts from the 1940s, these mountains were first called N. Eredvyrn or Ered Myrn “Black Mountains” (TI/124), later changed to “White Mountains” with numerous Elvish forms: N. Hebel Orolos >> Hebel Uilos (WR/137) >> Hebel or Ephel Nimrais (WR/137) >> Hebel or Ered Nimrath (WR/137, 167) >> Ered Nimras (WR/168), then briefly to Eredfain before finally Ered Nimrais (WR/288). In later writings it occasionally appeared with the proper Sindarin plural of orod: S. Eryd (PE17/168, WJ/385).
ered (pl. of orod “mountain”), nimp (“white”) + rais (pl. of ras “horn”) The original form of ras is probably rass with the final s dropped at the end of a polysyllable [HKF].