A seizure is a sudden burst of abnormal electrical activity in the brain that temporarily affects how a person moves, feels, or acts. During a seizure, the brain's normal patterns get disrupted, like static interrupting a clear signal. Some seizures cause a person to lose consciousness and experience uncontrollable shaking or muscle movements, while others might cause someone to briefly stare blankly, seem confused, or experience strange sensations.

Seizures can result from many causes: epilepsy (a condition where seizures happen repeatedly), high fevers in young children, head injuries, or other medical problems. They usually last from a few seconds to a few minutes. While seizures can look frightening, most don't cause lasting harm, and many people with seizure disorders live completely normal lives with proper medical care.

You might also hear the word used in other contexts, like when police make a seizure of illegal goods, meaning they take possession of them.