It’s interesting that you mention this, because I did find such a title floating around:
Kal Thak’hra - Clan Lord/Baron of a Clan.
Granted it's probably a fan construction, but it appears to follow what we know of Kilrathi so far (literally, “Senior most noble-person”).
Incidentally, nice thinking outside the box. As mentioned before, Kilrathi appears to make use of metathesis, so the idea of “Kal” and “Lak” having some relation to one another bears at least some examination.