Startle is defined as to scare or surprise someone or to be scared or surprised.(verb)
An example of to startle is to sneak up behind a friend and yell "Boo!"
The definition of a startle is a quick scare or surprise.(noun)
An example of a startle is a person jumping out from behind a bush and shouting when his friend wasn't expecting it.
See startle in Webster's New World College Dictionary
Origin: ME stertlen, to rush, stumble along, freq. of sterten: see start
See startle in American Heritage Dictionary 4
verb star·tled, star·tling, star·tles verb, transitive
Origin: Middle English stertlen, to run about
Origin: , from Old English steartlian, to kick; see ster-1 in Indo-European roots.
Learn more about startle