Pathology. a sudden, abnormal, involuntary muscular contraction, consisting of a continued muscular contraction (tonic spasm) or of a series of alternating muscular contractions and relaxations (clonic spasm).
2.
any sudden, brief spell of great energy, activity, feeling, etc.
Origin: 1350–1400; Middle English spasme < Latin spasmus < Greek spasmós convulsion, derivative of spân to draw a sword or cord, wrench (off), convulse
c.1400, from O.Fr. spasme, from L. spasmus "a spasm," from Gk. spasmos "a spasm, convulsion," from span "draw up, tear away, contract violently, pull," from PIE *spe- "stretch." Fig. sense of "a sudden convulsion" (of emotion, politics, etc.) is attested from 1817. The verb is recorded from 1900.