Meaning : Affected by involuntary jerky muscular contractions. Resembling a spasm.
Example :
Convulsive motions.
His body made a spasmodic jerk.
Spastic movements.
Synonyms : convulsive, spastic
Meaning : Occurring in spells and often abruptly.
Example :
Fitful bursts of energy.
Spasmodic rifle fire.
Synonyms : fitful