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defibrillator

American  
[dee-fahy-bruh-ley-ter, -fib-ruh-] / diˈfaɪ brəˌleɪ tər, -ˈfɪb rə- /

noun

Medicine/Medical.
defibrillators plural
  1. an agent or device for arresting fibrillation of the atrial or ventricular muscles of the heart.


defibrillator British  
/ dɪˈfaɪbrɪˌleɪtə, -ˈfɪb- /

noun

  1. med an apparatus for stopping fibrillation of the heart by application of an electric current to the chest wall or directly to the heart

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

Noun Inflected Forms

Etymology

Origin of defibrillator

First recorded in 1955–60; de- + fibrill(ation) + -ator

Explanation

A defibrillator is a machine that uses a current of electricity to restart a heart that is beating erratically. Doctors and EMTs use a defibrillator when they perform CPR on a patient. Defibrillator comes from defibrillation, literally "stopping fibrillation," or "stopping the heart from beating in an irregular way." The first defibrillators were demonstrated on dogs in 1899, but it wasn't until the 1950s that this method was used externally on humans, rather than during surgery. Even though movies often show doctors starting a stopped heart with a defibrillator, this isn't actually possible. What defibrillators do is closer to stopping an irregular heartbeat and shocking it into a normal rhythm.

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Surrounded by concerned and emotional teammates, he was given CPR on the pitch, before a portable machine called a defibrillator was used to reset his heart.

From BBC • Jun. 8, 2026

"There was no defibrillator, no oxygen, nothing. In the room, there was nothing to suggest that the patient was in hospital at home," Pinto said.

From Barron's • Apr. 23, 2026

The board said there was no defibrillator or oxygen tank in case of an emergency.

From The Wall Street Journal • Apr. 16, 2026

"The amount of time it took for CPR to take place and the defibrillator to get into the room."

From BBC • Mar. 20, 2026

The electricity from the defibrillator starts it back up.

From "The Miscalculations of Lightning Girl" by Stacy McAnulty

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