Hatzi- or Chatzi- (Greek: Χατζη-) is a prefix of Greek family names. It derives ultimately from the Arabic Hajji, denoting one who has successfully completed a pilgrimage.
In Christianity, the prefix is added when someone had committed the pilgrimage to Jerusalem. For example, if the surname was Stefanou, the name would then be Hatzistefanou after the journey.
References
Hatzi Wikipedia(Text) CC BY-SA