convulsion

(n) a sudden uncontrollable attack
- a paroxysm of giggling
- a fit of coughing
- convulsions of laughter
paroxysm, fit,
(n) violent uncontrollable contractions of muscles
(n) a violent disturbance
- the convulsions of the stock market
turmoil, upheaval,
(n) a physical disturbance such as an earthquake or upheaval

paroxysm fit turmoil upheaval

convulsive