The first name Kai is female and male.
The origin of the name Kai is not clear. It is presumably a Frisian short form of Gerard or Nikolaus, but as well of the Latin name Cajetanus and is of Celtic origin. Besides, Kai is a Hawaiian, Native American, Japanese and Chinese name. It is a name for boys and seldom for girls (from Latin Cajetana or Katharina).
Kai means “warrior” (from Frisian “kempe”), “victory of the people” (from Nikolaus), “spear strength”, “strong with the spear” (from Gerard), “from the town Gaeta” (from Cajetanus), in Celtic “spear bearer/thrower”, in Native American “willow tree”, in Japanese “pioneer”, in Chinese “triumph”, “victory”, in Hawaiian “ocean”, “sea”. For girls, Kai means “from the town Gaeta” (from Cajetana) or “pure” (from Katharina).