Erebor

noun. lonely mountain

ereb (“isolated, lonely”) + or (from orod “mountain”)

erebor

place name. Lonely Mountain

Sindarin name of the “Lonely Mountain” (LotR/1072). The initial element of this name is clearly ereb “single, alone” (SA/er), and the second element is likely a shorter version of orod “mountain” (as suggested by David Salo, GS/376).

Conceptual Development: In The Etymologies from the 1930s, this name appeared as N. Erebras (EtyAC/ERE), while in Lord of the Rings drafts from the 1940s, this name first appeared as N. Dolereb (TI/306) before being revised to N. Erebor (TI/142, 152, note #2).

Elements

Word	Gloss
ereb	“single, alone, lonely, single, alone, lonely, [N.] isolated”
orod	“mountain”