The Kiith-Sa is the ruling family of a Kiith. It also refers to the head of that family.
The Kiith-Sa holds the power of a Kiith, and in ancient times made all the decisions regarding the Kiith's future, its relations with other Kiiths and could move the entire clan to a new location. The Kiith-Sa is also the spokesperson for the clan and represents their Kiith in the Daiamid.
While in ancient times the Kiith-Sa's position was hereditary, in more modern times a Kiith-Sa is more likely to be elected, his or her merits depending on personal wealth or influence on Kiith members.