flabbergast
/ˈflabəɡɑːst
/verb [with object] (usually as adjective flabbergasted) informal
Surprise (someone) greatly; astonish: this news has left me totally flabbergasted...
- Well, I'd just like to say that I'm completely flabbergasted and astounded.
- Brian was flabbergasted, but not really surprised, not on a subconscious level.
- He was flabbergasted at the total complexity of the question.
Synonyms
astonish, astound, amaze, surprise, startle, shock, take aback, take by surprise;
dumbfound, strike dumb, render speechless, stun, stagger, stop someone in their tracks, take someone's breath away, confound, daze, overcome, overwhelm, nonplus, stupefy, disconcert, unsettle, bewilder
informal bowl over, knock for six, knock sideways, knock the stuffing out of, floor
British informal gobsmack
Origin
Late 18th century: of unknown origin.