Kai

Kai is a name with multiple independent origins across different language families. In Hawaiian, it means sea or ocean, while in Japanese it can carry meanings such as shell or restoration depending on the kanji used. In Welsh and Arthurian tradition, Cai is an early form of the name borne by one of King Arthur's knights, cognate with the Latin Caius, itself possibly of Etruscan origin meaning rejoice. Related forms across cultures include Kay, Cai, Kye, and the Scandinavian Kaj, where the name is also independently common.