Rite de passage
Rite de passage is a technical term in (mostly) Social Anthropology and Sociology. The word means any of the customs or ceremonials with which a given society marks important occasions in which a person moves from one status or condition to another, as in becoming adult, or married. There are common rites de passage to mark a mother's return to society after the birth, the naming of a child, puberty, initiation and so on. It is not obvious to all British people that dying, too, and the ceremonies associated with it, are rites de passage (the correct plural form): but in most cultures, including the Christian religion, death is passing from one world to the next, or another form of existence.
As is a French term, it should properly be written in italics, rite de passage and pronounced with a long '-ee-' vowel for rite. The plural should be written in the French way, rites de passage. It is pronounced precisely the same way as the singular - the '-s-' in rites is silent.
Many modern writers prefer to use the direct English translation, rite[s] of passage. It is less affected.