Search:

at the same time прощаться, попрощаться is used often and doesnt' have this 'parting forever' connotation.

Eg, Мы попрощались с гостями и стали мыть посуду - We said good bye to our guests and...

The 2 other examples are Спасибо which can be traced to Спаси Бог (г dropped out eventually), and здравствуйте which literally means 'будьте в здравии, в здоровье, be well, be in health' but is...