flesh out vs fill out

flesh out and fill out both are verbs.

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

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

Other synonyms of flesh out include round.

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

Other synonyms of flesh out include fat, fatten, fatten out, fatten up, plump, plump out.

flesh out (verb)	fill out (verb)
become round, plump, or shapely	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	make bigger or better or more complete
make fat or plump	write all the required information onto a form
	make fat or plump
	line or stuff with soft material
	supplement what is thought to be deficient