convulsion

An intense, paroxysmal, involuntary muscular contraction.

1850-1859, Charles Dickens, Household Words That immortal creature had gone over the proofs with great pains — had of course taken out the stiflings — hard-plungings, lungeings, and other convulsions — and had also taken out her weakenings and damagings of her own effects.

An uncontrolled fit, as of laughter; a paroxysm.

Violent turmoil.

Earthquakes and convulsions of nature shake Earth on a regular basis.

It would seem as if calm were necessary to convulsion; for the tranquillity of the last few months was again to be disturbed by political commotion.

Hysteric in nature.