To experience a strong reaction of surprise, shock or disbelief.
I'll be a monkey's uncle
Often preceded by well: expressing complete surprise or disbelief.
screw off
An expression of surprise or disbelief.
words fail someone
Someone is incapable of describing something with words, especially du …
hold onto your hat
One should prepare for a surprise or shock.
take aback
To surprise or shock; to discomfit.
holy fuck
Expression of terror, awe, surprise, shock, etc.