kənˈvʌlʃən ˈpæɹ.əkˌsɪz.əm ˈtɜːmɔɪl ʌpˈhi.vəl a physical disturbance such as an earthquake or upheaval a violent disturbance the convulsions of the stock market violent uncontrollable contractions of muscles a sudden uncontrollable attack a paroxysm of giggling a fit of coughing convulsions of laughter