convertibility n 1: the quality of being exchangeable (especially the ability to convert a currency into gold or other currencies without restriction) [ant: {inconvertibility}]
Convertibility \Con*vert`i*bil"i*ty\, n. The condition or quality of being convertible; capability of being exchanged; convertibleness. [1913 Webster] The mutual convertibility of land into money, and of money into land. --Burke. [1913 Webster]