Dwarvish
From Tolkien Gateway
Dwarvish was the secret tongue of the Dwarves, called by them Khuzdul, and seen only in a very few place-names (such as Khazad-dûm) and other fragments.
Dwarvish was the secret tongue of the Dwarves, called by them Khuzdul, and seen only in a very few place-names (such as Khazad-dûm) and other fragments.