A root in The Etymologies of the 1930s glossed “valiant”, its most notable derivative is the name S. Beren “Bold”. It had a variety of derivatives having to do with daring, such as ᴹQ. verya-/N. bertha- “to dare” and ᴹQ. verya/N. beren “bold”. The continued appearance of the name Beren in the later versions of The Silmarillion implies the root remained valid, but this name was only translated in The Etymologies of the 1930s, so it could have shifted in meaning.
Middle Primitive Elvish
thel(es)
root. sister
thelese
noun. *sister
auluta-
verb. [unglossed]
bay
root. [unglossed]
ber
root. valiant
iw
root. [unglossed], [ᴱ√] *fish
kalrondō
noun. hero
kaltwa
?. [unglossed]
khar
root. helmet
kharan
root. helmet
kharap
root. helmet
khlip
root. [unglossed]
An unglossed root in a rejected paragraph from the Quenya Verbal System of the 1940s (PE22/112 note #78).
kōmā
noun. [unglossed]
maiga
root. [unglossed]
An unglossed root appearing in the first version of Tengwesta Qenderinwa from the 1930s (TQ1) to illustrate certain patterns of root formation (PE18/66). It may have serving as the basis for ᴹQ. Maia, though this word was given different derivations later.
phan
root. [unglossed]
A deleted root in The Etymologies of the 1930s with no glosses or derivatives and no clear function (EtyAC/PHAN).
skil
root. [unglossed]
A root mentioned in passing in as a variant of ᴹ√KIL “divide” in The Etymologies of the 1930s, but it had no derivatives and appeared nowhere else (Ety/KIL).
stalgondō
noun. hero, dauntless man
stin
root. [unglossed]
stā
root. [unglossed]
torōmā
noun. [unglossed]
uruk
root. [unglossed]
A root in The Etymologies of the 1930s with no glosses or derivatives and no clear function (EtyAC/URUK).
us
root. [unglossed]
A root in The Etymologies of the 1930s with no glosses or derivatives and no clear function (EtyAC/US).
Tolkien gave this root in The Etymologies of the 1930s as ᴹ√THEL and extended form ᴹ√THELES with the gloss “sister” and derivatives like ᴹQ. seler and N. thêl of the same meaning, both derived from the extended root as made clear by the Noldorin plural thelei < ON. thelehi (Ety/THEL). Hints of the roots continued use appear in the 1959 term Q. meletheldi “love-sisters” for close female friends (NM/20). In notes from the late 1960s, Tolkien gave Q. nésa and S. nethel as the words for “sister”, both from the root √NETH. Nevertheless, I think it is worth retaining ᴹ√THEL(ES) to represent more abstract notions of “sisterhood” for the purposes of Neo-Eldarin, for “metaphorical sister”s as opposed to Q. nésa/S. nethel for sisters by blood.