Kalisfena (Russian, Slavic): Form of Greek name Kallisthena (beautiful strength/power), from roots kallos (beautiful) and sthenos (might, power, strength, ability). Obviously, this is also the source of the word “calisthenics.”
Kanza (Moorish Arabic): “Treasure.” The modern form is Kenza.
Katixa (Basque): Possibly a form of Katherine.
Kometitza (Basque): Possibly related to Medieval English name Comitessa, from Latin word comitissa (countess).
Kosenila (Russian, Slavic)
Kostantzia (Basque): Form of Constance.
Kristāna (Baltic): Probably a form of Christina.
Kaldor (German): Derived from Ancient Germanic name Chlodochar (famous army), from roots hlud (famous) and hari (army). Its best-known modern form is Lothar.
Kanutus (Swedish): Form of Knut, from Old Norse word knútr (knot).
Kartoka (Anglo–Scandinavian): Form of Kár-Tóki, from Old Norse root kárr (“curly-haired” or “reluctant, obstinant) and nickname Tóki (for names containing the element Þórr [Thor], “thunder”).
Kelagast (Slavic): The name of a 6th century nobleman. I couldn’t find a root for the first element, but the second seems to come from gost (guest).
Khutughtu (Mongolian): “Blessed.”
Khuwaylid (Arabic): “Immortal, eternal,” from root ḵalada (to last forever, to be everlasting). This was the name of Prophet Mohammad’s first father-in-law.
Kitan (Silesian–German): Nickname for Kristian.
Kitman (Moorish Arabic)
Könika (Swedish): Nickname for Konrad, which descends from Old High German name Kuonrat. Its roots are kuoni (strong, brave, bold) and rât (counsel).
Korp (Swedish): “Raven,” from Old Norse word korpr.
Kovals (Baltic, Livonian): Possibly related to Livonian word koval (smart) or Slavonic kowal (blacksmith).
Kresimir (Slavic): “Spark of the world” and “spark of peace,” from roots kresu (spark, light, rouse) and miru (world, peace). Modern forms are Krzesimir (Polish) and Krešimir (Croatian).
Külüg (Mongolian): “Hero.”
Kürşat (Turkic): “Hero, valiant, brave.”