What is the greek word for ok?

There isn't a single perfect Greek equivalent to the English "OK." "OK" is a relatively modern slang term, and doesn't have a direct translation in ancient or modern Greek.

Depending on the context, you might use several different words or phrases:

* εντάξει (entaxi): This is probably the closest single word and is very commonly used. It means "okay," "all right," or "fine."

* καλά (kala): This means "good" or "well," and can often be used as a synonym for "okay."

* δεν πειράζει (den peirazi): This translates to "it doesn't matter" or "it's okay," and is often used to respond to minor inconveniences.

The best choice depends entirely on the situation. `εντάξει (entaxi)` is the most versatile and generally accepted equivalent.