1. A type of epilepsy or a brain disorder in which clusters of nerve cells, or neurons, in the brain sometimes signal abnormally; resulting in the loss of consciousness, generalized muscle contractions, urinary incontinence, tongue biting and a condition with confusion and lethargy following the cessation of the stroke: Linda was subject to grand mal seizures which presented a risk for her pregnancies; so, she was frequently hospitalized during the months prior to giving birth to each of her children.

Some grand mal seizures may last for just a few seconds or they can continue for several minutes.

2. Etymology: from French grand mal, "big illness" and is an antonym of another type of epilepsy known as petit mal, "little illness".