The Greek word khairete (χαίρετε) is a plural imperative form of the verb "khairo" (χαίρω) meaning "to rejoice" or "to be well". It is used as a greeting or a farewell, similar to the English "Hello" or "Goodbye".
When the word appears in ancient literary works, it is usually translated into English as "Greetings", "Hail" or "Farewell", depending on the context.