to disturb or agitate suddenly as by surprise or alarm.
2.
to cause to start involuntarily, by or as by a sudden shock.
verb (used without object)
3.
to start involuntarily, as from a shock of surprise or alarm.
noun
4.
a sudden shock of surprise, alarm, or the like.
5.
something that startles.
Origin: before 1100;Middle Englishstertlen to rush, caper, equivalent to stert(en) to start + -(e)len-le, or continuing Old Englishsteartlian to kick, struggle
Related forms
star·tle·ment, noun
star·tler, noun
out·star·tle, verb (used with object), out·star·tled, out·star·tling.
un·star·tled, adjective
Synonyms 1. scare, frighten, astonish. See shock1.
c.1300, "run to and fro," frequentative of sterten (see start). Sense of "move suddenly in surprise or fear" first recorded 1530. Trans. meaning "frighten suddenly" is from 1595. The word retains more of the original meaning of start (v.).