Euthanasia

First attested in 1606, from Ancient Greek Îµá½Î¸Î±Î½Î±ÏƒÎ¯Î± (euthanasia), from Îµá½- (eu-, "good") + Î¸Î¬Î½Î±Ï„Î¿Ï‚ (thanatos, "death")

Full definition of euthanasia

(usually uncountable; plural euthanasias)

The practice of intentionally and painlessly killing a human being or animal for humane reasons, especially in order to end great suffering or poor quality of life.Euthanasia is the most difficult part of a veterinarian's job.
(obsolete) An easy death, or the means to bring about such a death.

1819 October 31, Thomas Jefferson, ,It would in time, it is to be hoped, effect a quiet euthanasia of the heresies of bigotry and fanaticism which have so long triumphed over human reason, and so generally and deeply afflicted mankind; but this work is to be begun by winnowing the grain from the chaff of the historians of his life.
1876, , Popular Science Monthly, Volume 8,This purely painless process, this descent by oblivious trance into oblivion, this natural physical death, is the true euthanasia; and it is the duty of those we call physicians to secure for man such good health as shall bear him in activity and happiness onward in his course to this goal. For euthanasia, though it be open to every one born of every race, is not to be had by any save through obedience to those laws which it is the mission of the physician to learn, to teach, and to enforce. Euthanasia is the sequel of health, the happy death engrafted on the perfect life.
1897, Bram Stoker, Dracula, Folio Society 2008, p. 273,For myself I could hold it in my account with God to find such an euthanasia for you, even at this moment if it were best.