The antonyms for the word "un-blamable" are quite plentiful. When something is un-blamable, it means that there is nothing to be blamed or criticized for. Antonyms for this word, therefore, would be anything that is blame-worthy or deserving of criticism. Some potential antonyms could include the terms "culpable," "accountable," "blamed," or "responsible." In each of these cases, there is something that can be pointed to as being the source of blame or criticism. Other potential antonyms could include words like "guilty" or "faulty," which both suggest that there is something wrong or problematic that can be identified.