inconvertible

Definitions of inconvertible

1. adjective

   not capable of being changed into something else
   “the alchemists were unable to accept the inconvertible nature of elemental metals”

   synonyms: untransmutable

   incommutable

   not subject to alteration or change
2. adjective

   used especially of currencies; incapable of being exchanged for or replaced by another currency of equal value
   synonyms: unconvertible, unexchangeable

   irredeemable

   (of paper money) not convertible into coin at the pleasure of the holder

   antonyms:

   convertible

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

   cashable, redeemable

   able to be converted into ready money or the equivalent