Definition: occurring in spells and often abruptly
Usage: fitful bursts of energy; spasmodic rifle fire
Similar words: sporadic
Definition: recurring in scattered and irregular or unpredictable instances
Usage: a city subjected to sporadic bombing raids
Synonyms: spasmodic, spastic, convulsive
Definition: affected by involuntary jerky muscular contractions; resembling a spasm
Usage: convulsive motions; his body made a spasmodic jerk; spastic movements
Similar words: unsteady
Definition: subject to change or variation
Usage: her unsteady walk; his hand was unsteady as he poured the wine; an unsteady voice