: feeling or showing intense shock, surprise, or wonder : utterly astonished
Every second person wore a blank flabbergasted expression, having just offered some gratuitous insult to a stranger, or, perhaps, received one. Myles na gCopaleen (Flann O'Brien)
That was the highlight of our career, when Vince Gill walked on stage one night and asked us to be the next members. We were flabbergasted, just speechless … Steve Wildsmith
But if the findings, published in 1996, surprised most scientists, recent research has left them flabbergasted. Sandra Blakeslee