This, of course, does not indicate any lack in the language or culture. Cheyennes still are friendly, even if they do not have a standard greeting in their language. They still greet each other, often nonverbally, as with a smile or a handshake. And they do let others know when they are sad to see them leave. Furthermore, Cheyenne has many words which have no easy translation in English or many other languages, so one cannot say that any language is richer or poorer than another.
There is a Cheyenne expression which is often used by men, which is a kind of greeting. It is "Haaahe." It has no word meaning, but, does still have important social meaning of recognition, solidarity, friendship. It is only used by a man toward another man.
Finally, in recent times some Cheyennes will sometimes use the verb nėstaévȧhósevóomȧtse when you are about to leave them. This literally means "I will see you again later," and has been borrowed from English.