Before proposing my opinion on the challenging question of righteous or wrongfulness of euthanasia, I have to clarify what I meant by this term by declaring the definition I do agree with that. Like many other terms, euthanasia has various meanings depending on the context and usage. The Oxford Dictionaries defines euthanasia as “The painless killing of a patient suffering from an incurable and painful disease or in an irreversible coma” and counts mercy killing, assisted suicide, and physician-assisted suicide as its synonyms. More specifically in medical terms, it means the practice of ending a life intentionally to relieve patient's suffering and pain.
However, these lexical definitions fail to determine adequately euthanasia, as they leave some possible actions open that although they may meet the definition, they cannot be seen as euthanasia.