A place in Tolkien's The Lord of the Rings, Carn Dûm was a mountain fortress and the capital of Angmar which was ruled by the Lord of the Nazgûl, also known as the witch-king. Lying in the northern reaches of the Misty Mountains, near the western edge of the mountains of Eriador, it was from here that the witch-king launched his assault on Arnor in 1409 (Third Age) during the reign of Araphor, Ninth King of Arthedain and in the ensuing battle, Cardolan and Rhudaur were overrun. The Tower of Amon Sûl was destroyed, but its palantír was saved and removed to Fornost. In 1851 (Third Age), Araval of Arthedain defeated Angmar and Carn Dûm was abandoned.
Carn Dûm is very difficult to translate since not only are there few clues as to the meaning of name, but it also seems to be derived from more than one language. The most obvious translation is based on the Sindarin word car(a)n, meaning 'red' and indeed the name Angmar, for the land of which Carn Dûm was the capital, is almost certainly Sindarin in origin. On the other hand, there is no known connection between Carn Dûm and the colour red, and Dûm is a Dwarvish word, one of the few whose translation is known.
Khazad-dûm, also known as Moria, means dwarf-hall or dwarf-cavern, and this seems to be a good description of a mountain fortress or citadel. Adjacent Mount Gundabad also has Dwarvish associations, so the possibility arises that Carn Dûm might once have been a Dwarvish city.
The possibility that Carn Dûm comes from the Black Speech must also be considered, but there is insufficient information about this language to make any evaluation useful. It is also possible that Carn Dûm is derived from the language of the human inhabitants of Angmar, but again this is speculation and the most likely translation remains 'Red Hall'.
The Languages of Tolkien - Ruth Noel