affright
alarm
amaze
ambush
astound
awe
awestrike
bedaze
bedazzle
bewilder
boggle
bowl down
bowl over
bushwhack
catch off-guard
catch unawares
come from behind
come upon unexpectedly
confound
daze
dazzle
do the unexpected
drop in on
dumbfound
dumbfounder
flabbergast
floor
overwhelm
paralyze
perplex
petrify
pounce upon
pull up short
shock
spring a surprise
spring upon
stagger
startle
strike dead
strike dumb
strike with wonder
stun
stupefy
surprise
take by surprise
take short
astonished
astonishes
astonishing
considerable
extraordinary
marvellous
uncommon
unprecedented
utmost
admonish