The Oxford Thesaurus An A-Z Dictionary of Synonyms - spasmodic adj.

1) spasmodical, paroxysmal, convulsive, jerky, jerking, sudden, Technical spastic: John was quite uneasy, unaware that Cynthia's spasmodic winking was due to a tic. 2) fitful, irregular, intermittent, arrhythmic, random, interrupted, sporadic, erratic, occasional, periodic, unsustained, discontinuous, pulsating, cyclic(al) , broken: Spasmodic peals of thunder shook the house.