#Perish (cited from Oxford Dictionary) Die, especially in a violent or sudden way: eg: a great part of his army perished of hunger and disease #Depart this life (often used in this way) eg: he departed this life with a putrid liver In most case, depart is rarely used as expression of death, but rather it refers to "leave" (often seen in airports)

"Departed" is a polite way to say dead, but it is also frequently used to mean "left the area," as in "The bus departed at ten thirty this morning. It is gone." "passed away" is also a polite way to say dead. I would say this is probably the most commonly used polite term, in America, at least. "perished" is usually only used in by news reporters. "Three people perished in the fire." "death" is a noun form of "dead."