euthanasia

eu·tha·na·sia

noun \ˌyü-thə-ˈnā-zh(ē-)ə\

Definition of EUTHANASIA

: the act or practice of killing hopelessly sick or injured individuals (as persons or domestic animals) in a relatively painless way for reasons of mercy; also : the act or practice of allowing a hopelessly sick or injured patient to die by taking less than complete medical measures to prolong life—called also mercy killing