"Ceremonial occasion" refers to an event that is marked by formal procedures and rituals. There are many synonyms for this phrase that can be used to describe different types of events. A "celebratory ceremony" is an occasion that is held to mark an important achievement or milestone. A "commemorative event" is held to remember a person, event, or occasion of historical significance. A "formal affair" is another term used to describe a ceremonial occasion, typically used to refer to high-end events, such as balls or galas. Lastly, a "rite of passage" refers to an event that signifies an important transition in someone's life, such as a graduation or a wedding.