Convulsion (noun)

1. A sudden, violent, involuntary contraction of the muscles.
2. A violent and uncontrolled muscular contraction or series of contractions.
3. A sudden, violent shaking of the body, caused by muscle contractions.

Origin:

The word convulsion is derived from the late 16th century from the latin word "convulsionem" which means "a violent shaking".

Examples:

1. The patient experienced convulsions as a side effect of the medication.
2. The child was suffering from convulsions due to the high fever.
3. The patient's convulsion lasted for several minutes.
4. The patient was in a state of convulsion.
5. The patient's body was wracked by convulsions.