fibrillation
Americannoun
-
the formation of fibrils, or fine fibers or filaments.
-
Pathology. uncontrolled twitching or quivering of muscle fibers, such as those of the heart.
noun
-
a local and uncontrollable twitching of muscle fibres, esp of the heart, not affecting the entire muscle. Atrial fibrillation results in rapid and irregular heart and pulse rate. In ventricular fibrillation , the heart stops beating
-
irregular twitchings of the muscular wall of the heart, often interfering with the normal rhythmic contractions
Etymology
Origin of fibrillation
First recorded in 1830–40; fibrillate + -ion
Compare meaning
How does fibrillation compare to similar and commonly confused words? Explore the most common comparisons:
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.
He said his struggle intensified following a heart scare during a training run, which led to him being diagnosed with atrial fibrillation - a heart rhythm condition.
From BBC ● Oct. 23, 2026
Doctors are changing their referral practices for the Watchman device because there has been a lot of evidence published in recent months about the risk of stroke for people with atrial fibrillation, Mahoney said.
From The Wall Street Journal ● Jul. 29, 2026
Even so, tea consumption has been associated with reduced risks of atrial fibrillation, heart failure and stroke, similar to caffeinated coffee.
From Science Daily ● Jul. 22, 2026
Recent analyses based on participant-reported health information found that consuming 1-3 cups of caffeinated coffee per day was not associated with a higher risk of atrial fibrillation or abnormal heart rhythm.
From Science Daily ● Jul. 22, 2026
When he developed ventricular fibrillation, a heart rhythm abnormality that can be fatal within minutes, the problem was quickly fixed.
From "Class Matters" by The New York Times
![]()
Random Word
Spin the wheel and learn a new word!
Get a wordDefinitions 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.