Medical Dictionary

atrial fibrillation

noun

Medical Definition of ATRIAL FIBRILLATION

:  very rapid uncoordinated contractions of the atria of the heart resulting in a lack of synchronism between heartbeat and pulse beat—called also auricular fibrillation

Learn More About

Browse

How to use a word that (literally) drives some people nuts.
Test your vocab with our fun, fast game
Ailurophobia, and 9 other unusual fears