Defibrillator (noun)

1. A medical device that delivers an electric shock to the heart in order to restore its normal rhythm.
2. A device used to restart a person's heart that has stopped beating.

Origin:

From de- + fibrillator, "that which separates fibers".

Examples:

1. The paramedics used a defibrillator to try and revive the patient.
2. The public access defibrillator was located in the school's lobby.
3. The defibrillator is an essential piece of equipment in an ambulance.
4. The defibrillator is used to treat people suffering from sudden cardiac arrest.
5. The defibrillator is a life-saving device that can help to restart a person's heart.