convulsion > define

noun

• A sudden uncontrollable attack.
  • usage: "a paroxysm of giggling"; "a fit of coughing"; "convulsions of laughter"
  • synonyms: paroxysm, fit
• Violent uncontrollable contractions of muscles.
• A violent disturbance.
  • usage: "the convulsions of the stock market"
  • synonyms: turmoil, upheaval
• A physical disturbance such as an earthquake or upheaval. .

• (n.) Any violent and irregular motion or agitation; a violent shaking; a tumult; a commotion.
• (n.) An unnatural, violent, and unvoluntary contraction of the muscular parts of an animal body.