/ˌʌpˈstɑːrtl/ (UP-start-ul)

Definitions

1. verb

to startle or surprise suddenly, often in a sudden, violent, or unexpected manner

“The loud explosion would upstartle anyone in its vicinity.”

2. noun

a sudden or violent startle

“The upstartle from the loud noise made her jump.”

3. noun

a person who behaves in a sudden or violent manner, often as a reaction to something

“The upstartle of the crowd was a sight to behold.”