The state or condition of being mistaken.

past participle of mistake

Erroneous. / (with a copula verb, often with about) Having an incorrect belief.

plural of mistaken identity

Falsely believing that someone is someone else. / (law) A defense in criminal law based on this situation, claiming that any eyewitnesses to a crime incorrectly thought that they saw the defendant.

Used before stating something that the speaker believes to be correct

wrongly, erroneously / by accident, by mistake, in error (without intention to do so)