envelope vs balloon

envelope and balloon both are nouns.

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

envelope (noun)	balloon (noun)
any wrapper or covering	large tough nonrigid bag filled with gas or heated air
a flat (usually rectangular) container for a letter, thin package, etc.	small thin inflatable rubber bag with narrow neck
the bag containing the gas in a balloon
the maximum operating capability of a system (especially an aircraft)
a natural covering (as by a fluid)
a curve that is tangent to each of a family of curves

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