timepiece vs timekeeper

timepiece and timekeeper both are nouns.

Word	Noun	Adjective	Verb	Adverb
timepiece	Yes	No	No	No
timekeeper	Yes	No	No	No

As nouns, timepiece and timekeeper are synonyms defined as:

timepiece and timekeeper: a measuring instrument or device for keeping time

Other synonyms of timepiece include horologe.

timepiece (noun)	timekeeper (noun)
a measuring instrument or device for keeping time	a measuring instrument or device for keeping time
	a clerk who keeps track of the hours worked by employees
	(sports) an official who keeps track of the time elapsed