A word translated as “base” (PE18/33, 60, 84; WJ/319) or in its plural form as “roots” (PE18/95). In The Etymologies of the 1930s Tolkien had ᴹQ. sundo “base, root, root-word” under the root ᴹ√SUD “base, ground” (Ety/SUD). The word Sundokarme “base structure” indicates a stem of sundo- (PE18/33, 84). In one place Tolkien gave its plural as sundur indicating a stem form of sundu- (PE18/95), but in another Tolkien had sundar “roots” indicating an alternate singular form sunda (UT/166). See S. thond “root” for a discussion of the vacillations on the possible etymologies of this word.
Conceptual Development: The Etymologies of the 1930s also had ᴹQ. numbe or núve “root, foundation” under the root {ᴹ√(N)DUM >>} ᴹ√(N)DUB “lay base, foundation, root; found”, but this entry was deleted (EtyAC/NDUB).
base