An easy or painless death, or the intentional ending of the life of a person suffering from an incurable or painful disease at his or her request.
The intentional termination of the life of one human being by another.
Related Information:
The American Medical Association, Council on Ethical and Judicial Affairs is strongly opposed to Mercy Killing, stating that "The intentional termination of the life of one human being by another is contrary to public policy, medical tradition and the most fundamental measures of human value and worth."
The forgoing of treatment (withholding) or stopping of medical treatment (withdrawing) is *not* the intentional termination of life.
Sources:
National Cancer Institute (NCI). Dictionary of Cancer Terms. Mercy Killing. Available at: http://www.cancer.gov/Templates/db_alpha.aspx?CdrID=457957
American Medical Association, Council on Ethical and Judicial Affairs. Report C A-88. Euthanasia. http://www.ama-assn.org/ama1/pub/upload/mm/369/ceja_ca88.pdf

