boggle

verbs

startle with amazement or fear
boggle
is a type of (narrower)
move or jump suddenly, as if in surprise or alarm
"She startled when I walked into the room"
jump, start, startle
hesitate when confronted with a problem, or when in doubt or fear
boggle
is a type of (narrower)
pause or hold back in uncertainty or unwillingness
"Authorities hesitate to quote exact figures"
hesitate, waffle, waver
overcome with amazement
"This boggles the mind!"
boggle, bowl over, flabbergast