fetch vs retrieve

fetch is a noun but retrieve is not a noun.

Word	Noun	Adjective	Verb	Adverb
fetch	Yes	No	Yes	No
retrieve	No	No	Yes	No

As verbs, retrieve is a hyponym of fetch; that is, retrieve is a word with a more specific, narrower meaning than fetch:

Other hyponyms of fetch include deliver.

fetch (noun)	retrieve (noun)
the action of fetching

fetch (verb)	retrieve (verb)
go or come after and bring or take back	recall knowledge from memory; have a recollection
remove	run after, pick up, and bring to the master
be sold for a certain price	go for and bring back
	get or find back; recover the use of