emyn (pl. of amon “hill”), muil (Dor. “twilight, shadow, vagueness”)
Sindarin
emyn muil
place name. Drear Hills
Emyn Muil
noun. drear hills
Emyn Muil
place name. the drear hills
Emyn Muil is a Sindarin name meaning "the drear hills"; the word emyn is the plural form of amon ("hill").
Hills between the river Anduin and the Dead Marshes (LotR/373), translated “Drear Hills” in Tolkien’s “Unfinished Index” of The Lord of the Rings (RC/334). It appears to be a combination of the plural of amon “hill” and muil, either an adjective meaning “drear” or a noun meaning “dreariness” (see its entry for further discussion).
Conceptual Development: In Lord of the Rings drafts from the 1940s, these hills went through many names: N. Duil Rain >> N. Emyn R(h)ain (TI/268), later N. Sern Lamrach >> N. Trandóran before finally settling on Ety Muil (TI/424).