A Dwarven city in the Blue Mountains translated “Hollowbold” (S/91) or “Dwarrowdelf” (WJ/209). Originally, this name was North Sindarin (NS.) Novrod, a translation of Khuzdul Tumunzahar “Hollowbold”, but its initial element NS. nôf fell out of common use and the name was reformed as Nogrod (WJ/209, 389, 414). The reformed name was reinterpreted as a combination of S. naug “dwarf” and grod “delving”, hence: “Dwarrowdelf” or “Dwarf-delving” (SA/naug, groth).
Conceptual Development: The name G. Nogrod appeared in the earliest Lost Tales (LT2/224) and N. Nogrod was translated “Dwarfmine” in Silmarillion drafts from the 1930s (LR/274). In The Etymologies it was translated “Dwarf-city” and given as a combination of N. naug “dwarf” and the root ᴹ√ROD or ᴹ√ROT “cave” (Ety/NAUK, EtyAC/NAUK). The more elaborate etymology given above was developed in conjunction with the Silmarillion revisions from the 1950s-60s (WJ/209, 389, 414).
naug (“dwarf”) + grod (“delving, underground dwelling”) Late substitution for Novrod (“hollow underground dwelling”) < nov (AS “hollow”) + grod (“excavation, underground dwelling”), which “retains the older Eldarin order with the adjectival element first”.