pacesetter vs pacemaker

pacesetter and pacemaker both are nouns.

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

As nouns, pacesetter and pacemaker are synonyms defined as:

Other synonyms of pacesetter include pacer.

As nouns, pacesetter and pacemaker are synonyms defined as:

pacesetter (noun)	pacemaker (noun)
a horse used to set the pace in racing	a horse used to set the pace in racing
a leading instance in its field	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