Some hills in South Ithilien (LotR/750). This name is translated “Hills of Arnen”, a combination of the plural of amon “hill” and the regional name Arnen (VT42/17).
Conceptual Development: In Lord of the Rings drafts from the 1940s, this name first appeared as N. Haramon (WR/359), later revised to N. Emyn Arnen (WR/363 note #3).
emyn (pl. of amon “hill”), ar (#from Dor. ar - “outside, beside”) + nen (“water”)