Earliest name for S. Nanduhirion appearing in Lord of the Rings drafts from the 1940s (RS/432), apparently starting with N. tum “valley” and ending with Ilk. celon “river”, but the meaning of the middle element is unclear. Roman Rausch suggested it might be related to Ilk. dimb- “sad, gloomy” (EE/1.14).
Noldorin
nanduhiriath
place name. Dimrill-dale
nanduhirion
place name. Dimrill-dale
tum dincelon
place name. Dimrill-dale
A precursor to S. Nanduhirion “Vale of Dim Streams” appearing in Lord of the Rings drafts from the 1940s (RS/433), apparently ending with the lenited class-plural hiriath of N. sîr “stream”, as suggested by Roman Rausch (EE/1.14).