A root in The Etymologies of the 1930s glossed “smoulder” with derivatives like ᴹQ. yúla/N. iûl “ember(s)” and ᴹQ. yulma/N. iolf “brand” (Ety/YUL). In all likelihood it was supplanted by the later root √YUL “drink”.

Neo-Eldarin: Despite it’s probable replacement by √YUL “drink”, I’d still recommend using some derivatives of ᴹ√YUL “smoulder” for purposes of Neo-Eldarin. Noldorin forms like iolf and iûl are not viable as derivatives in Sindarin, since initial yu- became the (vowel) y, for example: ýneg < ✶yūneke (VT47/41). But the Noldorin forms could be adapted into (Neo) Sindarin if they were derived from a Neo-Root ᴺ√YOL. Quenya forms could likewise be transferred to this root, or retained unmodified if we assume an occasional √YOL/YUL variation, similar to vowel variations like √SOK/SUK (PE18/45, 94). Assuming the existence of such a ᴺ√YOL/YUL Neo-Root would allow many of these 1930s forms to be salvaged without directly conflicting with √YUL “drink”.