Groez-Duil is the proudly carried self designation of the mountain dwarves of Thuzgol.
The Goblin Wars were followed by centuries of relative peace, during which it was decided that calling someone a dwarf was nondescript and insulting due to the complexities and fine nuances of the dwarven clan system. Foreigners, on the other hand, could not be expected to comprehend such subtleties, so the collective might of the clans was united under the designation of "Groez", with the "Duil" appended to appease the war-like Duil clan.