- cardiac fibrillation
- 1: An act or process of forming fibers or fibrils.
2a: A muscular twitching involving individual muscle fibers acting without coordination. b: Very rapid irregular contractions of the muscle fibers of the heart resulting in a lack of synchronism between heartbeat and pulse.
Definition from: Merriam-Webster's Medical Dictionary by Merriam-Webster Inc.
See also Understanding Medical Terminology.