Answer: convulsing

AnswerCrossword Clue
convulsing(of a person) Suffer violent involuntary contraction of the muscles, producing contortion of the body or limbs
convulsingCONVULSE, to shake violently
convulsing(of an emotion, laughter, or physical stimulus) Cause (someone) to make sudden, violent, uncontrollable movements
convulsingThrow (a country) into violent social or political upheaval