Synonyms for Irredeemable (same or very similar meaning)
WordNet sense 1 (insusceptible of reform):
irreclaimable, unredeemable, unreformableWordNet sense 2 (morally bad in principle or practice):
wicked, wickedWordNet sense 3 (used especially of currencies; incapable of being exchanged for or replaced by another currency of equal value):
inconvertible, unconvertible, unexchangeableFrom the ODE community, based on WordNetadd/edit