Dwimorberg
From Tolkien Gateway
Dwimorberg or Haunted Mountain was one of the White Mountains. To the west, there was the ancient hold of Dunharrow overlooking Harrowdale from the east.[1]
The mountain was brooding and black. On its lower slopes was the wood of Dimholt. Beyond its glen and behind a single standing stone, was the Dark Door, which led inside the Dwimorberg and the haunted Paths of the Dead.[1]
The wraiths of the Oathbreakers haunted the mountain, giving it its name. After Aragorn redeemed them, the Dwimorberg was haunted no longer.[2]
Etymology
The name means "haunted mountain".[source?] The first element is also seen in the Rohirric names Dwimordene (Lothlórien) and Dwimmerlaik (Witch-king). The second element means "mountain".[source?]