pacemaker
Americannoun
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Medicine/Medical. an electronic device implanted beneath the skin for providing a normal heartbeat by electrical stimulation of the heart muscle, used in certain heart conditions.
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Anatomy, Physiology. any specialized tissue that governs a rhythmic or cyclic biological activity, as the sinoatrial node of the heart that controls heartbeat.
noun
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a person, horse, vehicle, etc, used in a race or speed trial to set the pace
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a person, an organization, etc, regarded as being the leader in a particular field of activity
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Also called: cardiac pacemaker. a small area of specialized tissue within the wall of the right atrium of the heart whose spontaneous electrical activity initiates and controls the beat of the heart
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Also called: artificial pacemaker. an electronic device for use in certain cases of heart disease to assume the functions of the natural cardiac pacemaker
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Any of several usually miniaturized and surgically implanted electronic devices used to stimulate or regulate contractions of the heart muscle. Electrodes attached to the heart muscle conduct electrical signals generated from the pacemaker, which either provides constant electrical stimuli to regularize the heartbeat (fixed-rate pacemakers) or provides a stimulus only when electrical activity within the heart is abnormal (demand pacemakers). Pacemakers are used in the treatment of various arrhythmias.
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A part of the body, such as the specialized mass of cardiac muscle fibers of the sinoatrial node, that sets the pace or rhythm of physiological activity.
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Etymology
Origin of pacemaker
Explanation
A pacemaker is a medical device that controls a person's heartbeat. A patient only has a pacemaker implanted when his own heart isn't working well on its own. The human heart has a natural pacemaker that makes it beat at an appropriate rate to keep blood flowing throughout the body. Sometimes it doesn't work right, because of some kind of blockage or other problem that causes the heart to beat too slowly. In these cases, cardiologists — or heart doctors — will often surgically implant an electronic pacemaker as a replacement. Pacemaker research began in 1899, but it wasn't until 1958 that the first patients received these lifesaving devices.
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.
See Examples For:
The other main type is connected directly to the heart and, like a pacemaker, also sends regular electrical signals if the heart is beating too slowly.
From BBC ● Jun. 8, 2026
Investigators consider the octogenarian a “vulnerable adult” owing to her difficulty walking, pacemaker and a heart condition that required daily medication.
From The Wall Street Journal ● Feb. 24, 2026
Guthrie’s pacemaker app showed a disconnect from her phone.
From The Wall Street Journal ● Feb. 13, 2026
At 02:28, the app on her pacemaker, an implanted cardiac device, disconnected from her phone.
From BBC ● Feb. 10, 2026
In medicine, a new generation of pacemaker could regulate a person’s heartbeat for decades, rather than needing to be replaced every two years.
From "Reaching for the Moon" by Katherine Johnson
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While thousands of people in Northern Ireland are fitted with standard pacemakers, CRT devices are less common.
From BBC ● May 15, 2026
Because of Kipchoge’s use of wind-breaking pacemakers and other measures, the mark wasn’t eligible for a world record.
From The Wall Street Journal ● Apr. 26, 2026
It’s hundreds, thousands, and sometimes more than 100,000 people suing over life-changing physical harm from asbestos-laced baby powder, from NFL concussions, from pacemakers, hip implants, and other medical products.
From Slate ● Jan. 13, 2026
Semiconductors have enabled a slew of modern devices - from smartphones and laptops to video game consoles, pacemakers and solar panels.
From BBC ● Aug. 7, 2025
The procession is arranged according to height, the two shortest ushers leading—unless others of nearly the same height are found to be more accurate pacemakers.
From Etiquette by Post, Emily
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.