I. ˈstär-t ə l verb
( star·tled ; star·tling ˈstärt-liŋ, ˈstär-t ə l-iŋ)
Etymology: Middle English stertlen, frequentative of sterten to start
Date: 1530
intransitive verb
: to move or jump suddenly (as in surprise or alarm)
the baby startle s easily
transitive verb
: to frighten or surprise suddenly and usually not seriously
• star·tle·ment -mənt noun
II. noun
Date: 1714
: a sudden mild shock (as of surprise or alarm)