What is the Greek word for hi?

There isn't one single perfect equivalent of "Hi" in Greek, as the best translation depends on the context and level of formality. However, some common options include:

* Γεια (Gia): This is a very common and informal greeting, similar to "hi" or "hello." It's suitable for most casual situations.

* Χαίρετε (Chairete): This is a more formal and plural greeting, roughly translating to "greetings" or "hello" to multiple people.

* Γεια σας (Gia sas): This is a polite and formal greeting, suitable for addressing one or more people you don't know well. It's similar to "hello" or "good day."

So, depending on the situation, any of these could be used, but Γεια (Gia) is probably the closest single-word equivalent to a casual "hi."