Meaning : Used especially of currencies. Incapable of being exchanged for or replaced by another currency of equal value.
Synonyms : unconvertible, unexchangeable
Capable of being exchanged for or replaced by something of equal value.
Convertible securities.Meaning : Not capable of being changed into something else.
Example :
The alchemists were unable to accept the inconvertible nature of elemental metals.
Synonyms : untransmutable