1580s, "a violent and involuntary contraction of the muscular parts of the body," from Latin convulsionem (nominative convulsio) "cramp, convulsion," noun of action from past-participle stem of convellere "to tear loose," from assimilated form of com "with, together" (see con-) + vellere "to pluck, pull violently" (see svelte).
Meaning "any violent or irregular (social, political, etc.) motion, turmoil" is from 1640s. Of laughter, 1735. Related: Convulsions; convulsional.
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.
early 15c., "sudden attack, convulsion; periodic worsening of a disease," from Old French paroxysme, paroxime (13c.) and directly from Medieval Latin paroxysmus "irritation, fit of a disease," from Greek paroxysmos "irritation, exasperation," from paroxynein "to irritate, goad, provoke," from para- "beyond" (see para- (1)) + oxynein "sharpen, goad," from oxys "sharp, pointed" (from PIE root *ak- "be sharp, rise (out) to a point, pierce" ). Non-medical sense of "any sudden and violent action; convulsion, fit" is by c. 1600. Related: Paroxysmal.
1610s, "of the nature of or characterized by convulsion," from French convulsif, from Medieval Latin *convulsivus, from convuls-, past-participle stem of convellere "to pull away, to pull this way and that, wrench," from assimilated form of com "with, together" (see con-) + vellere "to pluck, pull violently" (see svelte). Meaning "producing or attended by convulsions" is from 1700. Related: Convulsively.
"pertaining to, of the nature of, or characterized by spasm; affected by spasms, convulsive," 1680s, from French spasmodique, from Medieval Latin spasmodicus, from Greek spasmōdes "of the nature of a spasm," from spasmos "a spasm, convulsion; wincing; violent movement" (see spasm) + -odes "like" (see -oid). Figuratively, "happening or operating by fits and starts; jerky," also "high-strung." Related: Spasmodically.
1570s, hickop, earlier hicket, hyckock, "a word meant to imitate the sound produced by the convulsion of the diaphragm" [Abram Smythe Palmer, "Folk-Etymology," London, 1882]. Compare French hoquet, Danish hikke, Persian hikuk, Hindi hichki, etc. Modern spelling first recorded 1788; An Old English word for it was ælfsogoða, so called because hiccups were thought to be caused by elves.