This root first appeared in The Etymologies of the 1930s as strengthened ᴹ√ÑGWAL “torment” with derivatives like ᴹQ. nwalka/N. balch “cruel” and N. baul “torment” (Ety/ÑGWAL). The root was given in an unstrengthened form √GWAL “suffer torment” in both the first and second versions of the Tengwesta Qenderinwa in a set of root variations along with √KWAL “die” and √KWEL “fade away” (TQ1: PE18/58; TQ2: PE18/103). Tolkien’s use of Q. nwalmë “torment” in Appendix E of The Lord of the Rings indicates the strengthened form remained valid, however (LotR/1123).
Neo-Eldarin: For purposes of Neo-Eldarin, I prefer to use this root only its strengthened form, reserving √GWAL for the less dire sense “be stirred, excited; emotion, movement of feelings” (PE17/154, 189).
This root appeared in a couple different notes from the late 1950s, as {√GWAL} >> √WAL “emotion, movement of feelings” in one (PE17/189) and as √GWAL “be stirred, excited” in the other (PE17/154). However, its one Sindarin derivative balch “fierce, ferocious” (PE17/154) requires the primitive form be √GWAL, since it demonstrates the Ancient Telerin sound change whereby labialized velars became labials (gw > b). This is further supported by the prevalence of w-forms in its Quenya derivations, since primitive ✶gw- would have remained w- for longer in Quenya (PE19/75).