- convulsive, spasmodic, spastic - affected by involuntary jerky muscular contractions; resembling a spasm; "convulsive motions"; "his body made a spasmodic jerk"; "spastic movements"
Antonym: steady (indirect, via unsteady)
- fitful, spasmodic - occurring in spells and often abruptly; "fitful bursts of energy"; "spasmodic rifle fire"
Antonym: continual (indirect, via sporadic)