exemplar vs pacemaker

exemplar and pacemaker both are nouns.

Word	Noun	Adjective	Verb	Adverb
exemplar	Yes	No	No	No
pacemaker	Yes	No	No	No

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

Other hyponyms of exemplar include beaut, beauty, pacesetter, pattern, prodigy.

exemplar (noun)	pacemaker (noun)
something to be imitated	a horse used to set the pace in racing
	an implanted electronic device that takes over the function of the natural cardiac pacemaker
	a specialized bit of heart tissue that controls the heartbeat
	a leading instance in its field