grand mal seizure; tonic-clonic seizure
Medical term for a major epileptic seizure involving loss of consciousness and convulsions. Contrasts with 小発作 (petit mal seizure).
See also: 小発作
He collapsed from a grand mal seizure.
Compound of 大 (dai, 'large') + 発作 (hossa, 'seizure, attack'). The reading ほっさ is a regular sound change from はっさ.