unring

verb2

1. •
   Hypothetically, to reverse the act of ringing, or the consequences of the action.

   • In a criminal trial, if the prosecution brings in inadmissible evidence that would unfairly prejudice the accused, a mistrial may be warranted. Having the judge admonish the jury to disregard the evidence might not be enough, as the saying goes, 'You can't unring the bell.'
2. •
   (literary) To remove a ring from.

   • Her lofty song commands in thrilling strains That new-raised woman snap her rusty chains, Unring her finger and unbind her breast. — 1979