"Form of Christian"
The name Christyan is commonly a male name from the "English" origin.
Christyan is a respelling of Christian in which the i of the second syllable is written as y, the same substitution seen in spellings such as Cristian and Kristian. Christian is an established English given name that derives from Latin Christianus. The spelling Christyan is a later form and does not carry a separate meaning.
Christian means "Anointed, Servant of Christ".
The pronunciation of Christyan is KRIS-chun.