J.R.R. Tolkien’s fictional language of the Dwarves was called Khuzdul.
Khuzdul is the secret language of the Dwarves in Tolkien’s legendarium. The Dwarves are said to have received it from their creator, Aulë, and to have guarded it closely rather than teaching it widely to other peoples.
Only a small amount of Khuzdul appears in Tolkien’s published fiction. The best-known examples include “Baruk Khazâd! Khazâd ai-mênu!” and the names Khazad-dûm and Zirakzigil. The language’s sound and structure were influenced in part by Semitic languages.
Khuzdul should not be confused with Sindarin or Quenya, which are Elvish languages, or with Adûnaic, the language associated with Númenor. Tolkien’s treatment of Khuzdul is comparatively limited, but its restricted use fits the Dwarves’ secrecy within the story.