ᴹ√SLIG “*entwine, thread; spider”
An unglossed root in The Etymologies of the 1930s, with derivatives like ᴹQ. lia/N. thlê “fine thread, spider filament” and ᴹQ. líne/N. thling “cobweb, [N.] spider” (Ety/SLIG). It is probably a later iteration of the primitive form ᴱ√LI+ya “unite many as one” from the Qenya Lexicon of the 1910s with derivatives like ᴱQ. lia “twine” and ᴱQ. liante “tendril” (QL/53), with analogous forms G. lind “twine” and G. -liont in the contemporaneous Gnomish Lexicon (GL/54).
ᴹ√SLIN “*fine, delicate”
An unglossed root in The Etymologies of the 1930s, with derivatives like ᴹQ. linda “fair” (blended with ᴹ√LIN² “sing”) and N. thlinn “fine, slender” (Ety/SLIN). It is probably a later iteration of the unglossed root ᴱ√SḶŘḶ (true form ᴱ√ÞḶÐḶ given in parenthesis) from the Qenya Lexicon of the 1910s with derivatives like ᴱQ. silda “slender” (QL/84). The connection is made more obvious by derivatives in the contemporaneous Gnomish Lexicon such as G. flidhra/thlidhra “willowy, graceful” and G. thlind “fine, slender” (GL/73).
ᴹ√(S)LIT “swiftly[?] speed[?]”
The forms √SLIT and √LIT appear in a rejected page of roots from the Quenya Verbal System of the 1940s with some unclear glosses, probably “swiftly, speed”; they were the basis for the past-tense form lhinte “sped” of otherwise unattested verb ᴹQ. lhit- (PE22/127). This root might be connected to later Q. linta “swift” from the Namárië poem (LotR/377; PE17/63), though elsewhere Tolkien indicated that Q. linta (< *lim-tā?) was the equivalent of S. lim¹ “quick, swift” (PE17/147).
ᴹ√SLIW “sickly”
A root in The Etymologies of the 1930s glossed “sickly”, with derivatives like ᴹQ. laiwa/N. flaew “sick, sickly, ill” and ᴹQ. líve/N. fliw “sickness” (Ety/SLIW). The root was first written as ᴹ√LIW (EtyAC/LIW). It is probably a later iteration of the unglossed root ᴱ√LEẆE from the Qenya Lexicon of the 1910s with derivatives ᴱQ. leuke “sick, ill; pallid, wan” and ᴱQ. leume “sickness” (QL/53).
√(S)LON “sound, (general word for) noise”
The root forms √LON and √SLON appearing in a list of roots for sound words from 1959-60 as a general root for “noise”; it had derivates Q. hlóna/S. lhôn “a noise” and Q. hlonite “phonetic” (PE17/138). Similar forms appeared in the Quendi and Eldar essay written in the same period (WJ/395; VT39/9) and in a torn half-sheet associated with that document, the primitive form *slōn was glossed “sound” (VT48/29).
ᴹ√SLUS “whisper”
A root in The Etymologies of the 1930s with variants ᴹ√SLUS and ᴹ√SRUS; it was glossed “whisper” with derivatives like ᴹQ. lussa- “to whisper” and ᴹQ. lusse/N. thloss/floss “whispering sound” (Ety/SLUS). The only sign of ᴹ√SRUS was the variant form N. thross of N. thloss/floss.