flesh out vs clear up

flesh out and clear up both are verbs.

Word	Noun	Adjective	Verb	Adverb
flesh out	No	No	Yes	No
clear up	No	No	Yes	No

As verbs, clear up is a hypernym of flesh out; that is, clear up is a word with a broader 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
clear up: make clear and (more) comprehensible

Other hypernyms of flesh out include clarify, elucidate.

flesh out (verb)	clear up (verb)
become round, plump, or shapely	free (the throat) by making a rasping sound
add details, as to an account or idea; clarify the meaning of and discourse in a learned way, usually in writing	finish a task completely
make fat or plump	make free from confusion or ambiguity; make clear
	make clear and (more) comprehensible
	become clear