late 14c., "sudden violent muscular contraction," from Old French spasme (13c.) and directly from Latin spasmus "a spasm," from Greek spasmos "a spasm, convulsion," from span "draw up, tear away, contract violently, pull, pluck," from PIE *spe- "stretch." Figurative sense of "a sudden convulsion" (of emotion, politics, etc.) is attested from 1817.
