A word in notes on Eldarin Hands, Fingers and Numerals from the late 1960s meaning “tip, point”, also used to refer to fingers and toes, especially in compounds (VT47/10). It was derived from the root √TIL. Drafts of these document instead had tile and tilma, of which Tolkien said:
> The difference between tilma, tile and inga was that the former could point in any direction, but inga was only applied to shapes pointing upwards and meant “top”; and whereas til- was usually applied to ends notably thinner and sharper than the stem, inga referred primarily to position and could be used of tops relatively broad (VT47/28).
Conceptual Development: The Qenya Lexicon of the 1910s had ᴱQ. {tilme >> tilla >>} tille “eyelash” under the early root ᴱ√TILI (QL/92).
Neo-Quenya: Since tille referred to fingers and tilde to mountains, I would assume tille was more narrow and blunt, as opposed to tilde which was sharper and more angular. I would also use tille for “eyelash” as in Early Qenya, or less ambiguously ✱hentille.
This word is most notable as the final element of the name Taniquetil “High White Peak”, a derivation Tolkien used for most of his life. In the Quendi and Eldar essay of 1959-60, Tolkien said tilde “is not a mountain peak, but a fine sharp point” (WJ/417). However, its primitive form tilde was glossed “peak” in notes from around 1965 (PE17/186), ᴹQ. tilde was glossed “spike, horn” in The Etymologies of the 1930s under from the root ᴹ√TIL “point, horn” (Ety/TIL; EtyAC/TIL), and ᴱQ. tilde “tip, peak” appeared in the Poetic and Mythological Words of Eldarissa of the 1910s (PME/92), though it was merely “point” in the contemporaneous Qenya Lexicon under the early root ᴱ√TILI (QL/92).
Note that some of the above forms were presented incorrectly in their original publications. In The Etymologies as published in The Lost Road the gloss of tilde was given as “point, horn” identical to its root (LR/393), but Carl Hostetter and Patrick Wynne corrected this “spike, horn” in their Addenda and Corrigenda to the Etymologies (VT46/19). The primitive form was given as tilte as originally published in Parma Eldalamberon #17 (PE17/186), but in a post to the Vinyë Lambengolmor Discord Server (VLDS), Christopher Gilson corrected this to tilde: discord.com.
Neo-Quenya: For purposes of Neo-Quenya, I would assume tilde refers to a variety of pointy things of various sizes, including spikes, horns, and mountain peaks, especially if they are sharply pointed. In the case of mountains, I would further assume it refers to the tip or peak rather than the entire mountaion.