flesh out vs expound

flesh out and expound both are verbs.

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

As verbs, flesh out and expound are synonyms defined as:

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

Other synonyms of flesh out include dilate, elaborate, enlarge, expand, expatiate, exposit, lucubrate.

As verbs, expound is a hyponym of flesh out; that is, expound 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
expound: state

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