spasm n.

late 14c., "sudden violent muscular contraction," from Old French spasme (13c.) and directly from Latin spasmus "a spasm," from Greek spasmos "a spasm, convulsion; wincing; violent movement," from span "draw (a sword, etc.), pull out, pluck; tear away, drag; suck in; slurp down; contract violently," which is perhaps from a PIE *(s)peh- "to draw, set in motion (violently)," hence "to stretch." The figurative sense of "a sudden convulsion" (of emotion, politics, etc.) is attested by 1817.

1900, from spasm (n.). Related: Spasmed; spasming.