occasion vs ceremonial

occasion and ceremonial both are nouns.

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

As nouns, ceremonial is a hyponym of occasion; that is, ceremonial is a word with a more specific, narrower meaning than occasion:

occasion (noun)	ceremonial (noun)
an event that occurs at a critical time	a formal event performed on a special occasion
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

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

occasion (verb)	ceremonial (verb)
give occasion to