ᴹ√SAG root. “*bitter, poison”
An unglossed root in The Etymologies of the 1930s with derivatives like ᴹQ. sangwa/N. saew “poison” and ᴹQ. sára/N. saer “bitter” (Ety/SAG). Later poison words were derived from √SLOY, but I think this root is worth retaining in Neo-Eldarin as the basis for “bitter”.
Reference ✧ Ety/SAG
*ᴱ√ǶEN+U root. “*poison”
A root in the Qenya Lexicon of the 1910s given as ᴱ√HEN+U with derivatives having to do with poison (QL/40). Many of the Qenya derivatives begin with f, such as ᴱQ. heno “venom, poison” beside feno and ᴱQ. fent “serpent”, versus ᴱQ. henuva “venomous, poisonous”. Thus I think the true root may have been ᴱ√ǶEN+U or it at least had such a variant, since initial and intervocalic ƕ [xʷ] became f in Early Qenya. Its Gnomish cognates likewise mostly began with f, such as G. fem “venom” and G. fenog “venomous” (GL/34). There are no signs of this root in Tolkien’s later writing.
Reference ✧ QL/40 ✧ HEN+U