clerk vs shipping clerk

clerk and shipping clerk both are nouns.

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

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

clerk: an employee who performs clerical work (e.g., keeps records or accounts)
shipping clerk: an employee who ships and receives goods

clerk (noun)	shipping clerk (noun)
an employee who performs clerical work (e.g., keeps records or accounts)	an employee who ships and receives goods
a salesperson in a store

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