convertible vs convertibility

convertible and convertibility both are nouns.

Word	Noun	Adjective	Verb	Adverb
convertible	Yes	Yes	No	No
convertibility	Yes	No	No	No

convertible (noun)	convertibility (noun)
a car that has top that can be folded or removed	the quality of being exchangeable (especially the ability to convert a currency into gold or other currencies without restriction)
a sofa that can be converted into a bed
a corporate security (usually bonds or preferred stock) that can be exchanged for another form of security (usually common stock)

convertible (adjective)	convertibility (adjective)
capable of being exchanged for or replaced by something of equal value
designed to be changed from one use or form to another
capable of being changed in substance as if by alchemy