convertible

a sofa that can be converted into a bed

capable of being changed in substance as if by alchemy

a corporate security (usually bonds or preferred stock) that can be exchanged for another form of security (usually common stock)

capable of being exchanged for or replaced by something of equal value

“convertible securities”

a car that has top that can be folded or removed

designed to be changed from one use or form to another

“a convertible sofa”