sales rep vs clerk

sales rep and clerk both are nouns.

Word	Noun	Adjective	Verb	Adverb
sales rep	Yes	No	No	No
clerk	Yes	No	Yes	No

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

sales rep: a person employed to represent a business and to sell its merchandise (as to customers in a store or to customers who are visited)
clerk: a salesperson in a store

sales rep (noun)	clerk (noun)
a person employed to represent a business and to sell its merchandise (as to customers in a store or to customers who are visited)	an employee who performs clerical work (e.g., keeps records or accounts)
	a salesperson in a store

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