ceremony vs initiation

ceremony and initiation both are nouns.

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

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

ceremony (noun)	initiation (noun)
the proper or conventional behavior on some solemn occasion	the act of starting something for the first time; introducing something new
any activity that is performed in an especially solemn elaborate or formal way	an act that sets in motion some course of events
a formal event performed on a special occasion	wisdom as evidenced by the possession of knowledge
	a formal entry into an organization or position or office