To be taken aback or bewildered by an unexpected event; to be at a loss for how to react.
突然の質問に面食らって、うまく答えられなかった。
I was taken aback by the sudden question and couldn't answer well.
予想外の来客に家族全員が面食らった。
The whole family was taken aback by the unexpected visitor.
面接で奇妙な要求をされて、候補者は面食らっていた。
The candidate was taken aback when asked a strange request in the interview.