unexchangeable

from WordNet (r) 3.0 (2006)
unexchangeable
    adj 1: not suitable to be exchanged [ant: {exchangeable}]
    2: used especially of currencies; incapable of being exchanged
       for or replaced by another currency of equal value [syn:
       {inconvertible}, {unconvertible}, {unexchangeable}] [ant:
       {convertible}, {exchangeable}]
    

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