Kai
[kaɪ]Meaning
uncertain; possibly a Frisian diminutive of Gerhard, Nicolaas, Cornelis or Gaius, or Hawaiian for "sea"
Background Story
Behind the Name gives the meaning of the Frisian and Scandinavian name Kai as uncertain, possibly a diminutive of Gerhard, Nicolaas, Cornelis or Gaius, and records it as the name of a boy captured by the Snow Queen in an 1844 fairy tale by Hans Christian Andersen. It spread from Germany and Scandinavia and became popular in the English-speaking world and elsewhere in Western Europe around the end of the 20th century. A separate entry gives Kai as a short form of Kaia, and another gives it as the Hawaiian word for "sea". Wiktionary notes the medieval Danish Kaj as possibly of Roman origin, Latinized as Caius, and the German Kai as possibly from a West Frisian pet form of Gerard, Cornelius, Nicholas or Kampe, "warrior".

Related Names
Kya
A name of uncertain origin, potentially meaning 'from the ocean' or 'victory' in various cultures
Kaikala
A Telugu-speaking community, also called Kaikalas or Karikala Bhaktulu
Kainoa
A Hawaiian given name
Keo
Recorded as a given name in Hawaiian and Lao
Kim
An English short form of Kimball or Kimberley, a Scandinavian short form of Joachim, and a Korean surname
Kir
Nassie
Ola Kai
Umi
Sea or ocean in Japanese