1. rapid, uncoordinated contractions of muscle fibers in the heart, causing an irregular heartbeat
Usage: medical term; commonly abbreviated as AFib or VFib depending on the type
2. the process of breaking down into small fibers or fiber-like structures
Usage: technical; used in materials science and biology

Examples

• The patient was diagnosed with atrial fibrillation after experiencing irregular heartbeats.
• Fibrillation of the ventricles is a life-threatening cardiac emergency.
• Her doctor prescribed medication to prevent fibrillation episodes.
• The fibrillation of muscle tissue can be observed under a microscope.
• Untreated fibrillation increases the risk of stroke.
• The cardiologist used an EKG to detect signs of fibrillation.