Rite (noun)

1. A religious or other solemn ceremony or act.
2. A traditional custom or practice associated with a particular event, occasion, or celebration.

Origin:

Late middle english: from old french, from latin ritus 'religious custom, ritual'.

Examples:

1. The rite of baptism is a sacrament in many Christian churches.
2. The rite of passage from adolescence to adulthood.
3. The funeral rites were performed by the priest.
4. The wedding rite was performed in a traditional manner.
5. The rite of spring is a celebration of the arrival of spring.