/ kənˈvʌlʃn; NAmE / noun [ usually pl. ]
1.
a sudden shaking movement of the body that cannot be controlled :
The child went into convulsions.
SYN fit
2.
a sudden important change that happens to a country or an organization
SYN upheaval
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WORD ORIGIN
mid 16th cent. (originally in the sense cramp, spasm ): from Latin convulsio(n-) , from the verb convellere , from con- together + vellere to pull.