call up vs retrieve

call up is a noun but retrieve is not a noun.

Word	Noun	Adjective	Verb	Adverb
call up	Yes	No	Yes	No
retrieve	No	No	Yes	No

As verbs, call up and retrieve are synonyms defined as:

Other synonyms of call up include call back, recall, recollect, remember, think.

call up (noun)	retrieve (noun)
an order to report for military duty

call up (verb)	retrieve (verb)
recall knowledge from memory; have a recollection	recall knowledge from memory; have a recollection
get or try to get into communication (with someone) by telephone	run after, pick up, and bring to the master
bring forward for consideration	go for and bring back
call to arms; of military personnel	get or find back; recover the use of
cause to become available for use, either literally or figuratively