euthanasia

Euthanasia conducted with the full, informed consent of the person.

Ending a person's life by a direct action, such as a lethal injection.

Allowing a person to die by withholding or withdrawing life-sustaining treatment.

Euthanasia performed on a person who is able to provide informed consent, but does not.

Euthanasia conducted when the explicit consent of the individual is unavailable, e.g., when in a persistent vegetative state.

To make the practice of euthanasia legal by law.

To carry out the act of euthanasia.

To carry out the act of euthanasia, often as a regular procedure. 'Practise' is the verb in BrE; 'practice' is the verb in AmE.