expand vs expound

expand and expound both are verbs.

Word	Noun	Adjective	Verb	Adverb
expand	No	No	Yes	No
expound	No	No	Yes	No

As verbs, expand and expound are synonyms defined as:

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

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

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

expand (verb)	expound (verb)
grow vigorously	add details, as to an account or idea; clarify the meaning of and discourse in a learned way, usually in writing
exaggerate or make bigger	state
become larger in size or volume or quantity
expand the influence of
make bigger or wider in size, volume, or quantity
add details, as to an account or idea; clarify the meaning of and discourse in a learned way, usually in writing
extend in one or more directions