flesh out vs instance

flesh out is not a noun while instance is a noun.

Word	Noun	Adjective	Verb	Adverb
flesh out	No	No	Yes	No
instance	Yes	No	Yes	No

As verbs, instance is a hyponym of flesh out; that is, instance is a word with a more specific, narrower meaning than flesh out:

flesh out: add details, as to an account or idea; clarify the meaning of and discourse in a learned way, usually in writing
instance: clarify by giving an example of

flesh out (noun)	instance (noun)
	an item of information that is typical of a class or group
	an occurrence of something

flesh out (verb)	instance (verb)
become round, plump, or shapely	clarify by giving an example of
add details, as to an account or idea; clarify the meaning of and discourse in a learned way, usually in writing
make fat or plump