Arthur's brother. A variant of Gaius; which is a more common form of the name in Britain. A diminutive of Cajus, frequently used as an independent name in Wales. Rejoicer.

Cain

Biblical Hebrew Irish Welsh

Possession; or possessed Spear; possessed. In the Bible Cain was the first murderer having killed his brother Abel in a fit of jealousy. Archaic. Clear water.

Caio

Welsh

Joy.