Originally Posted by Lord of Hunger
According to recent studies, the Darth title has recently been revealed as originating from the Rakata Infinite Empire. D'arth was a term for their emperor, but also meant triumph over death or immortal.
It was originally thought that the title was a shortened version of Dark Lord of the Sith, but the revelations of how much of the Infinite Empire's culture was passed down to the Sith discounts this theory.
The Rakata word was Daritha, not D'arth.
Darr tah meant Triumph over death.