ceremony vs pageant

ceremony and pageant both are nouns.

Word	Noun	Adjective	Verb	Adverb
ceremony	Yes	No	No	No
pageant	Yes	No	No	No

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

ceremony (noun)	pageant (noun)
the proper or conventional behavior on some solemn occasion	an elaborate representation of scenes from history etc; usually involves a parade with rich costumes
any activity that is performed in an especially solemn elaborate or formal way	a rich and spectacular ceremony
a formal event performed on a special occasion