N. silith n. “light of Silpion, †silver” (Category: Moon)
A word in The Etymologies of the 1930s, for which Tolkien said “For *silif N has silith, by assimilation to or from influence of †Ithil” (Ety/SIL). Since N. silif was derived from primitive ᴹ✶silimē for the “light of Silpion” (Ety/SIL), it seems silith was a more modern replacement of it, probably with the same meaning. As it was influenced by Ithil “Moon”, it probably had the sense “*moonlight” after Silpion was lost.
Reference ✧ Ety/SIL ✧ “light of Silpion, †silver”
|N. silif > silith||[siliv] ? [siliθ]||✧ Ety/SIL|