1. n. Med. A sudden involuntary and abnormal muscular contraction, usually causing pain: Maggie felt a muscle spasm in her back. Tom's jaw muscles had gone into spasm. Synonyms. convulsion, throe, fit, twitch, paroxysm, cramp.
2. n. A sudden convulsive movement or emotion: a spasm of coughing, spasm of grief, spasm of laughter. Synonyms. fit, seizure, convulsion, paroxysm, spell, outburst, burst, eruption.
3. n. (usually followed by of) colloq. A sudden and brief outburst of intense activity: a spasm of creativity.
From Middle English spasme, from Old French spasme, from Latin spasmus, from Greek spasmos, from span, «to draw, pull».