√(N)DUR root. “love, feeling of special concern with, care for, or interest in things”
Counterpart to the root √N(D)IL, this root first appeared in a marginal note from The Etymologies of the 1930s as ᴹ√NDUR or ᴹ√DUR “bow down, bend (down), obey, serve”, an elaboration of ᴹ√NDŪ “go down, sink, set (of Sun)” (Ety/NDŪ; EtyAC/NDŪ). In the Quenya Verbal System of the 1940s, ᴹ√NDUR was glossed “grow, be dark”, no doubt in connection to N./S. dûr “dark” (PE22/103), but later this “dark” word was connected more directly to √NDU “under, down”. Indeed, in a 1955 letter to David Masson, Tolkien gave √(N)DUR an origin distinct from √N(D)U, basing it on an independent root √DUR “to show special interest in things” (PE17/152); there was also an unglossed and deleted root ᴹ√DUR in The Etymologies of the 1930s (EtyAC/DUR). However, in a 1967 letter to Mr. Rang, -(n)dur again meant “to serve” (Let/386).
Neo-Eldarin: For purposes of Neo-Eldarin, I think it is best to keep the connection between √NDUR “bow down = serve” and √NDU “descend”. As for the semantic distinctions between -(n)dil and -(n)dur, see the entry on the root √N(D)IL for details.
References ✧ NM/20; PE17/151-152, 167
A deleted root in The Etymologies of the 1930s with no glosses or derivatives and no clear function (EtyAC/DUR).
Reference ✧ EtyAC/DUR
ᴹ√N(D)UR root. “bow down, bend (low), obey, serve; grow/be dark”
References ✧ Ety/NDŪ; EtyAC/NDŪ; PE22/103