This root first appeared as ᴹ√RAS “stick up (intr.)” in The Etymologies of the 1930s with derivatives like ᴹQ. rasse and N. rhas or rhasg “horn (especially on living animal, but also applied to mountains)” (Ety/RAS; EtyAC/RAS). It reappeared as ᴹ√RASA “stick up” on an rejected page of roots in the Quenya Verbal System from the 1940s (PE22/127). Finally, √RAS “horn” appeared in Common Eldarin: Noun Structure of the early 1950s, but that was merely the last appearance of the root in Tolkien’s published writings. Q. rassë and S. rass “horn” continued to appear regularly as an element in mountain names in the 1950s and 60s.
Primitive elvish
til
root. point, horn
tilte
noun. peak
taltā
adjective. tottering, unsteady
pendā
adjective. sloping
ras
root. horn, horn; [ᴹ√] stick up
rass
noun. horn
teg
root. line
Tolkien used a number of similar roots as the basis for “line” words throughout his life. The earliest of these appeared in the Qenya Lexicon as ᴱ√TEHE [teχe] “pull” (gloss marked with a “?” by Tolkien) with derivatives like ᴱQ. tea “straight”, ᴱQ. telya “attractive; importunate”, and ᴱQ. tie “line, direction, route, road” (QL/90), the last of these surviving more or less unchanged all the way into the published version of The Lord of the Rings (LotR/377). The early root ᴱ√TEHE also had derivatives in the contemporaneous Gnomish Lexicon such as G. tê “mark, line; track; path”, G. tî or tion “straight”, and G. tîr “honest; esteem, regard, honour”, originally “straight, upright” (GL/69, 71). Primitive ᴱ✶tegna > ᴱQ. tína/ᴱN. tain “straight” from Early Noldorin Word-lists from the 1920s may represent a shift in the form of the root to ✱ᴱ√TEGE (PE13/153, 165).
In The Etymologies of the 1930s the root appeared as {ᴹ√TEƷ >>} ᴹ√TEÑ “line, direction” with derivatives like ᴹQ. tie/N. tê “line, way” and ᴹQ. téra/N. tîr “straight, right” (Ety/TEƷ, TEÑ). In the Outline of Phonology Tolkien gave √TEG “line”, whereas √TEÑ was given as the basis for Q. tenna “a thought, notion, idea” and thus clearly with a different meaning; see the entry √TEÑ for further discussion. In any case it is clear that Tolkien considered various ancient velar consonants for the second consonant of this root, all ultimately vanishing in the child languages with similar vocalic effects: 1910s teχ-, 1920s teg-, 1930s {teʒ- >>} teñ- and 1950s teg-.
Neo-Quenya: For purposes of Neo-Eldarin, I would assume this root was √TEƷ in order to preserve the validity of the word téma “series”. This is because Tolkien kept vacillating on the development of gm, but usually had gm > ngw, so that teg-mā > tengwa, not téma.
The root √TIL was used for “pointy thing” for much of Tolkien’s life, most notably as the final element in the name Q. Taniquetil “High White (or Snow) Peak”. Its earliest appearance was as unglossed ᴱ√TILI⁽⁾ or ᴱ√T͡YILI (probably the true form) in the Qenya Lexicon of the 1910s, where it had derivatives like ᴱQ. til⁽⁾ “a hair”, ᴱQ. tilde “point”, and ᴱQ. tille “eyelash” (QL/92). It was constrasted ᴱ√TILI⁽⁾ which had derivatives like ᴱQ. tilu- “shine (blue)” and ᴱQ. Tilio “Sirius” (QL/92). There is no connection between √TIL and “shine” in Tolkien’s later writings, with roots like √SIL or √TIN being used for that purpose instead.
The Etymologies of the 1930s had ᴹ√TIL “point, horn” with derivatives like ᴹQ. tilde/N. till “spike, horn” and ᴹQ. neltil/N. nelthil (Ety/TIL). The root √TIL “point” was mentioned a couple times in notes from the late 1960s in connection to finger-names (VT47/26, 28).