Xenia (Greek)
Xenia (Greek: ξενία, xenía) is the Greek word for the concept of hospitality, or generosity and courtesy shown to those who are far from home. It is often translated as "guest-friendship" (or "ritualized friendship") because the rituals of hospitality created and expressed a reciprocal relationship between guest and host.
The Greek god Zeus is sometimes referred to as Zeus Xenios, meaning he was god of, among other things, travelers. This created a particular religious obligation to be hospitable to travelers, but guests also had responsibilities, beyond reciprocating hospitality.
Read more about Xenia (Greek): Overview, In The Iliad, In The Odyssey