clerk vs timekeeper

clerk and timekeeper both are nouns.

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

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

clerk: an employee who performs clerical work (e.g., keeps records or accounts)
timekeeper: a clerk who keeps track of the hours worked by employees

clerk (noun)	timekeeper (noun)
an employee who performs clerical work (e.g., keeps records or accounts)	a measuring instrument or device for keeping time
a salesperson in a store	a clerk who keeps track of the hours worked by employees
	(sports) an official who keeps track of the time elapsed

clerk (verb)	timekeeper (verb)
work as a clerk, as in the legal business