hot-air balloon vs balloon

hot-air balloon and balloon both are nouns.

Word	Noun	Adjective	Verb	Adverb
hot-air balloon	Yes	No	No	No
balloon	Yes	No	Yes	No

As nouns, balloon is a hypernym of hot-air balloon; that is, balloon is a word with a broader meaning than hot-air balloon:

hot-air balloon: balloon for travel through the air in a basket suspended below a large bag of heated air
balloon: large tough nonrigid bag filled with gas or heated air

hot-air balloon (noun)	balloon (noun)
balloon for travel through the air in a basket suspended below a large bag of heated air	large tough nonrigid bag filled with gas or heated air
	small thin inflatable rubber bag with narrow neck

hot-air balloon (verb)	balloon (verb)
	become inflated
	ride in a hot-air balloon