• Webster's Revised Unabridged Dictionary
    • n Convulsionary A convulsionist.
    • a Convulsionary Pertaining to convulsion; convulsive. "Convulsionary struggles."
    • ***
Century Dictionary and Cyclopedia
    • convulsionary Pertaining to convulsion; of the nature of muscular convulsions: as, convulsionary struggles.
    • convulsionary Causing or resulting from violent disturbance or agitation.
    • n convulsionary pl. convulsionaries (-riz). One who is subject to convulsions; specifically [capitalized], one of a class of Jansenists in France who gained notoriety by falling into convulsive spasms and by other extravagant actions, supposed to be accompanied by miraculous cures, in response to a supposed miraculous influence emanating from the tomb of a pious Jansenist, François de Pâris, in the cemetery of St. Médard near Paris, who died in 1727. They continued to exist for more than fifty years.
    • ***
Chambers's Twentieth Century Dictionary
    • adjs Convulsionary pertaining to convulsions
    • ***


Webster's Revised Unabridged Dictionary
Cf. F. convulsionnaire,
Chambers's Twentieth Century Dictionary
L. con, inten., and vellĕre, vulsum, to pluck, to pull.


In literature:

Yes, I have seen these wretched Convulsionaries writhing their limbs and foaming at their mouths.
"A Philosophical Dictionary, Volume 5 (of 10)" by François-Marie Arouet (AKA Voltaire)