expand vs balloon

expand is not a noun while balloon is a noun.

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

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

Other hyponyms of expand include billow, inflate, intumesce, swell, swell up, tumefy, tumesce.

expand (noun)	balloon (noun)
	large tough nonrigid bag filled with gas or heated air
	small thin inflatable rubber bag with narrow neck

expand (verb)	balloon (verb)
grow vigorously	become inflated
exaggerate or make bigger	ride in a hot-air balloon
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