Sindarin equivalent of Endórë “Middle-earth”, derived from the same primitive form because in Sindarin [[s|[mb], [nd] became [mm], [nn]]] (LotR/1115).
Conceptual Development: In The Etymologies from the 1930s, the form N. Emerin appeared with the same translation but a completely different derivation (Ety/MBAR). In later writings, Tolkien generally derived S. Ennor from the root √ENED “centre, middle” (Let/384, PE17/26). He considered several alternate derivations, from √ENET or √HEN(ET) (VT41/16), but these reflected his uncertainty of the proper form of the root √ENED, not of S. Ennor itself.
topon. 'Middle-earth'. Poetic form ennorath. Q. Endor, Endóre. >> ennorath