Euthanasia, also known as assisted suicide, physician-assisted suicide (dying) , doctor-assisted dying (suicide) , and more loosely termed mercy killing, basically means to take a deliberate action with the express intention of ending a life to relieve intractable (persistent, unstoppable) suffering. Some interpret euthanasia as the practice of ending a life in a painless manner. Many disagree with this interpretation, because it needs to include a reference to intractable suffering.