'Convertibility' definitions:

Definition of 'convertibility'

(from WordNet)
noun
The quality of being exchangeable (especially the ability to convert a currency into gold or other currencies without restriction) [ant: inconvertibility]

Definition of 'Convertibility'

From: GCIDE
  • 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]