Meaning

noun a sudden involuntary movement

verb to stimulate to action

verb move or jump suddenly, as if in surprise or alarm

originFrom Middle English startlen, stertlen, stertyllen (“to rush, stumble along”), from Old English steartlian (“to kick with the foot, struggle, stumble”), equivalent to start + -le. Cognate with Old Norse stirtla (“to hobble, stagger”), Icelandic stirtla (“to straighten up, erect”). Compare also Middle English stertil (“hasty”). More at start.

Etymology from Wiktionary, CC BY-SA 3.0