- 瞠目结舌 [chēng mù jié shé]
- be struck dumb; all at sea; be wide-eyed and not make a sound; be so awed (at the sight of) that one couldn't speak; (He) is flabbergasted and has nothing to say.; make sb. open his eyes; One's mouth opens wide with surprise.; gape; stare at ..., tongue-tied; stare dumbfounded; stare tongue-tied; wide-eyed and tongue-tied
The guide was ready enough with his usual pattern on the history of the place, but as soon as you began to question him on anything outside that, he was all at sea.
The miraculous effect of medical herbs has raised some conservative eyebrows.