spasmodic adj.

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.

word-forming element meaning "like, like that of, thing like a ______," from Latinized form of Greek -oeidēs (three syllables), from eidos "form," related to idein "to see," eidenai "to know;" literally "to see" (from PIE *weid-es-, from root *weid- "to see"). The -o- is connective or a stem vowel from the previous element. Often implying an incomplete or imperfect resemblance to the thing indicated.