Fibrillation (noun)

1. An abnormal quivering or twitching of muscle fibers.
2. An irregular and uncoordinated contraction of the muscle fibers of the heart, typically resulting in a rapid and irregular heartbeat.

Origin:

Early 19th century: from modern latin fibrillatio(n-), from fibrillare "to form into fibers", from latin fibra "fiber".

Examples:

1. He was diagnosed with atrial fibrillation, a condition where the heart's upper chambers quiver irregularly.
2. The patient's heart was in fibrillation, and the doctors had to act fast to get it back to normal rhythm.
3. The electrical impulses that cause ventricular fibrillation are chaotic and ineffective.
4. Atherosclerosis can cause atrial fibrillation.
5. Fibrillation is a serious condition that requires immediate medical attention.