khan 1 
(kän, k
ăn)
n.1. A ruler, an official, or an important person in India and some central Asian countries.
2. A medieval ruler of a Mongol, Tatar, or Turkish tribe.
[Ultimately (partly via Urdu, khān) from Persian khān, from Old Turkic xān, title of subordinate Central Asian khans; akin to Old Turkic xāǧān, overlord of other khans, probably of non-Turkic Central Asian origin. Sense 2, from Middle English caan, chan, from Old French kaan, ultimately (partly via Mongol qā'ān) from Old Turkic xāǧān.]