a sofa that can be converted into a bed - sofa bed
a corporate security (usually bonds or preferred stock) that can be exchanged for another form of security (usually common stock) - convertible security
a car that has top that can be folded or removed
Adjective
capable of being changed in substance as if by alchemy "is lead really transmutable into gold?" "ideas translatable into reality"
designed to be changed from one use or form to another "a convertible sofa" "a convertible coupe"
capable of being exchanged for or replaced by something of equal value "convertible securities"