Tumunzahar

The essay Of Dwarves and Men in volume XI of The History of Middle-earth suggests that Tumunzahar was occupied by either the Firebeard or the Broadbeam clan. Based purely on the word order used in that source, the Dwarves of Tumunzahar appear to have been Firebeards.

Tumunzahar was the name of this city in the Khuzdul language of the Dwarves. That language is little known, but we do have versions of the same name in other tongues: Elvish Nogrod and Mannish Hollowbold. Nogrod simply means 'Dwarf-dwelling' or 'Dwarf-halls', and does not appear to be a direct translation of the Dwarvish name (not least because Tumunzahar lacks the element khazad, 'Dwarf'). The alternative Hollowbold is a more realistic possibility. It comes from old words meaning a 'carved dwelling', and so this is a plausible (though far from definitive) interpretation of the Dwarvish name Tumunzahar.