church officer vs elder

church officer and elder both are nouns.

Word	Noun	Adjective	Verb	Adverb
church officer	Yes	No	No	No
elder	Yes	Yes	No	No

As nouns, elder is a hyponym of church officer; that is, elder is a word with a more specific, narrower meaning than church officer:

Other hyponyms of church officer include churchwarden, deacon, Protestant deacon, sacristan, sexton, verger, vestryman, vestrywoman.

church officer (noun)	elder (noun)
a church official	a person who is older than you are
	any of various church officers
	any of numerous shrubs or small trees of temperate and subtropical Northern Hemisphere having white flowers and berrylike fruit

church officer (adjective)	elder (adjective)
	used of the older of two persons of the same name especially used to distinguish a father from his son