This name first appeared in Silmarillion drafts from the early 1930s as ᴹQ. Silma >> Ilma >> Ilmen as a name for the “Place of Light”, home of the stars (SM/240-1). It reappeared in the mid-30s as a word for “Starlight” (LR/205), and also appeared in The Etymologies as a derivative of ᴹ√GIL, alongside (and perhaps an element of) Ilmen “region above air where stars are” (Ety/GIL).
Qenya
silme
noun. moonlight, light of Silpion, †silver
silmerosse
proper name. Glimmering Rain
ilma
proper name. Starlight
nú
proper name. Moon
A name for the moon in linguistic notes from 1930s (PE21/38, 41), perhaps a derivative of the root ᴹ√NDŪ “go down”, though this root usually applied to the Sun. Its dual form Nunt referred to both the sun and moon (PE21/38).
A name of Silpion from Silmarillion drafts from the 1930s (LR/210), also appearing in The Etymologies as compound of silme “silver (light)” and rosse “rain” (Ety/ROS¹, SIL).