√THIL root. “shine silver; white light”
Tolkien frequently used the root √THIL as the basis for “moon” words in Elvish. The first appearance of this root was ᴱ√ÞILI a variant of ᴱ√SILI “*gleam” from the Qenya Lexicon of the 1910s (QL/83). The normal “moon” words in this period were ᴱQ. Sil and G. Sil (QL83; GL/67). A rejected Gnomish variant Thil “the moon” indicates Tolkien considered ᴱ√ÞILI, but did not commit to it (GL/72). However, in The Etymologies of the 1930s Tolkien gave unglossed ᴹ√THIL with derivatives like ᴹQ. Isil and N. Ithil “Moon, (lit.) Sheen” (Ety/I²; THIL). Tolkien stuck with these “Moon” words thereafter, and the root √THIL was mentioned regularly in Tolkien’s later writings (Let/425; PE17/66; PE22/136).
References ✧ Let/425; PE17/66, 188; PE22/136; SA/sil
References ✧ Ety/I², RIL, SIL, THIL; PE22/100, 112