homily vs sermon

homily and sermon both are nouns.

Word	Noun	Adjective	Verb	Adverb
homily	Yes	No	No	No
sermon	Yes	No	No	No

As nouns, sermon is a hypernym of homily; that is, sermon is a word with a broader meaning than homily:

homily: a sermon on a moral or religious topic
sermon: an address of a religious nature (usually delivered during a church service)

Other hypernyms of homily include discourse, preaching.

homily (noun)	sermon (noun)
a sermon on a moral or religious topic	an address of a religious nature (usually delivered during a church service)
	a moralistic rebuke