early 14c., from Latin ritus "religious observance or ceremony, custom, usage," perhaps from PIE root *re- "to reason, count." Rite of passage (1909) is translated from French rite de passage, coined by French anthropologist Arnold van Gennep (1873-1957).
the rite of baptism
Risorgimento
risotto
risque
Ritalin
ritardando
rite
ritual
ritualistic
Ritz
ritzy
rival