ceremonial vs occasion

ceremonial and occasion both are nouns.

Word	Noun	Adjective	Verb	Adverb
ceremonial	Yes	Yes	No	No
occasion	Yes	No	Yes	No

As nouns, occasion is a hypernym of ceremonial; that is, occasion is a word with a broader meaning than ceremonial:

Other hypernyms of ceremonial include affair, function, social affair, social function, social gathering, social occasion.

ceremonial (noun)	occasion (noun)
a formal event performed on a special occasion	an event that occurs at a critical time
	a formal or official social gathering or ceremony of people
	a rational motive for a belief or action
	an opportunity to do something
	the time of a particular event

ceremonial (adjective)	occasion (adjective)
marked by pomp or ceremony or formality

ceremonial (verb)	occasion (verb)
	give occasion to