Kai is a name used in several languages and with different origins. Kai, male name used as a diminutive of other names in various languages of Northern Europe and Scandinavia, for example, Gerhard, Nicolaas, Cornelis or Gaius. Kai, maori name for boy very popular in New Zealand. Kai, unisex name of Hawaiian origin that means sea. Kay, female name in Swedish, variant of Kaja coloring page