An old Sith tongue was used by the Sith, an ancient order of malevolent Force-practitioners, as a secret language. An example of words in that language were krataa and irluuk, which meant "death" and "fate", respectively. The Sith Master Darth Sidious, who came to rule the galaxy as Emperor, could speak in Sith tongue, as could his apprentice, Darth Vader. During a mission to Ryloth, the two Sith Lords spoke in the old tongue while in Drua's village—to avoid having the native Twi'leks understand them—as they discussed the fate of the villagers. In the village, Sidious and Vader used the aforementioned Sith words krataa and irluuk as aliases respectively.
- Lords of the Sith (First appearance)