fibrillation (n.)youdaoicibaDictYouDict[fibrillation 词源字典]
1842, "state of being fibrillar" (that is, "arranged in fibrils"), noun of action from fibrillate (v.). Especially "a quavering in the fibrils of the muscles of the heart" causing irregular beating (1882).[fibrillation etymology, fibrillation origin, 英语词源]